[CrOS Settings] Move OS device strings from settings strings

This CL moves chromeOS strings for devices page  from
settings_strings.grdp to os_settings_strings.grdp. It continues
the process of moving all chromeOS specific strings.

Bug: 967883
Change-Id: I903af5b573f9773edefba354a82b93c826c2de11
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2067390
Commit-Queue: Nnamdi Theodore Johnson-kanu <tjohnsonkanu@google.com>
Reviewed-by: Kyle Horimoto <khorimoto@chromium.org>
Cr-Commit-Position: refs/heads/master@{#747054}

chrome/app/os_settings_strings.grdp

@@ -232,6 +232,12 @@
   <message name="IDS_OS_SETTINGS_TOUCHPAD_REVERSE_SCROLL_LABEL">
     Reverse scrolling <ph name="LINK_BEGIN">&lt;a&gt;</ph>Learn more<ph name="LINK_END">&lt;/a&gt;</ph>
   </message>
+  <message name="IDS_SETTINGS_DEVICE_TITLE" desc="Name of the settings page which displays device and peripheral settings.">
+    Device
+  </message>
+  <message name="IDS_SETTINGS_SCROLL_LABEL" desc="In Device Settings, the title above the radio buttons to choose the scrolling behavior.">
+    Scrolling
+  </message>
 
   <!-- Personalization Page (OS settings) -->
   <message name="IDS_OS_SETTINGS_PERSONALIZATION" desc="Name of the OS settings page which displays personalization preferences.">

chrome/app/settings_strings.grdp

@@ -2870,14 +2870,6 @@
 
   <!-- Device Page -->
   <if expr="chromeos">
-    <message name="IDS_SETTINGS_DEVICE_TITLE" desc="Name of the settings page which displays device and peripheral settings.">
-      Device
-    </message>
-    <!-- Touchpad -->
-    <message name="IDS_SETTINGS_SCROLL_LABEL" desc="In Device Settings, the title above the radio buttons to choose the scrolling behavior.">
-      Scrolling
-    </message>
-
     <!-- Storage -->
     <message name="IDS_SETTINGS_STORAGE_TITLE" desc="In Device Settings, the title for storage management.">
       Storage management