Update strings related to ARC external storage settings.

This CL updates the strings to follow the latest spec.

Bug: 954228
Test: builds
Change-Id: Ibe49b3dea0bfecbb1413d78079ddf5d9c4d3d90f
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1787764Reviewed-by: Michael Giuffrida <michaelpg@chromium.org>
Commit-Queue: Naoki Fukino <fukino@chromium.org>
Cr-Commit-Position: refs/heads/master@{#693854}

chrome/app/chromeos_strings.grdp

@@ -1709,7 +1709,7 @@
     Explore the device's content in the Files app.
   </message>
   <message name="IDS_REMOVABLE_DEVICE_ALLOW_PLAY_STORE_ACCESS_MESSAGE" desc="Text of notification message to navigate users to the ARC settings page. If user clicks a button in the notification, the page opens.">
-    Allow Play Store applications to access this device via Settings.
+    To allow full file system access for apps from Google Play, go to Settings.
   </message>
   <message name="IDS_REMOVABLE_DEVICE_PLAY_STORE_APPS_HAVE_ACCESS_MESSAGE" desc="Text of notification message to navigate users to the ARC settings page. If user clicks a button in the notification, the page opens.">
     Play Store applications have access to this device.

chrome/app/settings_strings.grdp

@@ -4815,10 +4815,10 @@
       External storage preferences
     </message>
     <message name="IDS_SETTINGS_STORAGE_ANDROID_APPS_ACCESS_EXTERNAL_DRIVES_NOTE" desc="Label for the additional note for the subpage for setting preferences for external storage.">
-      Google Play Store applications may require access to external storage devices in order to read and write files and folders on them.
+      Apps from Google Play may require full file system access to read and write files on external storage devices. Files and folders created on the device are visible to anyone who uses the external drive.
     </message>
     <message name="IDS_SETTINGS_STORAGE_EXTERNAL_STORAGE_LIST_HEADER" desc="Header of the list of external storage devices for the subpage for setting preferences for external storage.">
-      Available USB devices will appear here.
+      Available devices will appear here.
     </message>
 
     <!-- Power -->