[CrOS Tether] Update "enable GmsCore notifications" UI.

This UI is shown on the settings page when a phone tells the Chromebook
that it does not have GmsCore notifications enabled.

Note: This CL's contents were already landed in
https://chromium-review.googlesource.com/c/chromium/src/+/894729.
However, part of that CL needed to be merged to the M-65 branch, so I'm
re-landing two separate CLs and only merging the other one to the M-65
branch.

Bug: 793936, 672263
Cq-Include-Trybots: master.tryserver.chromium.linux:closure_compilation
Change-Id: I647fd141415bf4d255405eec4989aebf19aef9e8
Reviewed-on: https://chromium-review.googlesource.com/898547Reviewed-by: Steven Bennetts <stevenjb@chromium.org>
Commit-Queue: Kyle Horimoto <khorimoto@chromium.org>
Cr-Commit-Position: refs/heads/master@{#534181}

chrome/app/settings_strings.grdp

@@ -1628,25 +1628,28 @@
       Unable to detect your phone
     </message>
     <message name="IDS_SETTINGS_INTERNET_GMSCORE_NOTIFICATIONS_TITLE" desc="Title of the section which explains how to enable Google Play Services notifications on an Android phone in order to use Instant Tethering.">
-      Google Play Services notifications are required for Instant Tethering
+      To use Instant Tethering, turn on notifications for Google Play Services.
     </message>
     <message name="IDS_SETTINGS_INTERNET_GMSCORE_NOTIFICATIONS_ONE_DEVICE_SUBTITLE" desc="Subtitle of the section which explains how to enable Google Play Services notifications. This subtitle is used when only one phone needs to have its notifications enabled.">
-      On your '<ph name="PHONE_NAME">$1<ex>Google Pixel</ex></ph>', enable notifications by following these steps:
+      On your '<ph name="PHONE_NAME">$1<ex>Google Pixel</ex></ph>':
     </message>
     <message name="IDS_SETTINGS_INTERNET_GMSCORE_NOTIFICATIONS_TWO_DEVICES_SUBTITLE" desc="Subtitle of the section which explains how to enable Google Play Services notifications. This subtitle is used when two phones need to have their notifications enabled.">
-      On your '<ph name="PHONE_NAME_1">$1<ex>Google Pixel</ex></ph>' and '<ph name="PHONE_NAME_2">$2<ex>Google Pixel 2</ex></ph>', enable notifications by following these steps:
+      On your '<ph name="PHONE_NAME_1">$1<ex>Google Pixel</ex></ph>' and '<ph name="PHONE_NAME_2">$2<ex>Google Pixel 2</ex></ph>':
     </message>
     <message name="IDS_SETTINGS_INTERNET_GMSCORE_NOTIFICATIONS_MANY_DEVICES_SUBTITLE" desc="Subtitle of the section which explains how to enable Google Play Services notifications. This subtitle is used when three or more phones need to have their notifications enabled.">
-      On your devices, enable notifications by following these steps:
+      On your devices:
     </message>
-    <message name="IDS_SETTINGS_INTERNET_GMSCORE_NOTIFICATIONS_FIRST_STEP" desc="First instruction for how to enable Google Play Services notifications on an Android phone. This step teaches the user how to look at Google Play Services settings.">
-      Go to Settings &gt; Apps &amp; notifications &gt; All apps &gt; Google Play Services.
+    <message name="IDS_SETTINGS_INTERNET_GMSCORE_NOTIFICATIONS_FIRST_STEP" desc="First instruction for how to enable Google Play Services notifications on an Android phone. This step teaches the user how to look at notification settings.">
+      Go to Settings &gt; Apps &amp; notifications &gt; Notifications.
     </message>
-    <message name="IDS_SETTINGS_INTERNET_GMSCORE_NOTIFICATIONS_SECOND_STEP" desc="Second instruction for how to enable Google Play Services notifications on an Android phone. This step teaches the user how to look at notification settings when already viewing Google Play Services settings.">
-      Tap on App notifications.
+    <message name="IDS_SETTINGS_INTERNET_GMSCORE_NOTIFICATIONS_SECOND_STEP" desc="Second instruction for how to enable Google Play Services notifications on an Android phone. This step teaches the user how to look at notification settings for the Google Play Services app.">
+      Tap App notifications &gt; Google Play services.
     </message>
     <message name="IDS_SETTINGS_INTERNET_GMSCORE_NOTIFICATIONS_THIRD_STEP" desc="Third instruction for how to enable Google Play Services notifications on an Android phone. This step teaches the user how to enable notifications when already viewing noticiations settings for Google Play Services.">
-      Check that app notifications are "On". If not, toggle to enable.
+      Turn on Google Play services.
+    </message>
+    <message name="IDS_SETTINGS_INTERNET_GMSCORE_NOTIFICATIONS_FOURTH_STEP" desc="Fourth instruction for how to enable Google Play Services notifications on an Android phone. This step teaches the user how to enable the Instant Tethering notification channel for Google Play Services.">
+      Scroll to the bottom of the screen and turn on Instant Tethering, if it appears. If it doesn't, you're all set.
     </message>
     <message name="IDS_SETTINGS_INTERNET_NO_NETWORKS_MOBILE_DATA" desc="Text shown when viewing the Mobile data page when there are no cellular or tether networks available.">
       No mobile connection found. Turn on Instant Tethering on your other devices and try again. &lt;a target="_blank" href="<ph name="URL">$1<ex>https://google.com/</ex></ph>"&gt;Learn more&lt;/a&gt;

chrome/browser/resources/settings/internet_page/internet_subpage.html

@@ -143,6 +143,7 @@
               <li>$i18n{gmscoreNotificationsFirstStep}</li>
               <li>$i18n{gmscoreNotificationsSecondStep}</li>
               <li>$i18n{gmscoreNotificationsThirdStep}</li>
+              <li>$i18n{gmscoreNotificationsFourthStep}</li>
             </ol>
           </div>
         </template>

chrome/browser/ui/webui/settings/md_settings_localized_strings_provider.cc

@@ -1096,6 +1096,8 @@ void AddInternetStrings(content::WebUIDataSource* html_source) {
        IDS_SETTINGS_INTERNET_GMSCORE_NOTIFICATIONS_SECOND_STEP},
       {"gmscoreNotificationsThirdStep",
        IDS_SETTINGS_INTERNET_GMSCORE_NOTIFICATIONS_THIRD_STEP},
+      {"gmscoreNotificationsFourthStep",
+       IDS_SETTINGS_INTERNET_GMSCORE_NOTIFICATIONS_FOURTH_STEP},
       {"tetherConnectionDialogTitle",
        IDS_SETTINGS_INTERNET_TETHER_CONNECTION_DIALOG_TITLE},
       {"tetherConnectionAvailableDeviceTitle",