[remoting] Add what's new strings for M74 mobile clients

Change-Id: I843a4e6d667c7b86dfd95c092414bb478d9f860b
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1637048
Commit-Queue: Yuwei Huang <yuweih@chromium.org>
Commit-Queue: Jamie Walch <jamiewalch@chromium.org>
Auto-Submit: Yuwei Huang <yuweih@chromium.org>
Reviewed-by: Jamie Walch <jamiewalch@chromium.org>
Cr-Commit-Position: refs/heads/master@{#664876}

remoting/resources/remoting_strings.grd

@@ -689,8 +689,7 @@ Remote computers with non US-English keyboards may receive incorrect text input.
 For information about privacy, please see the Google Privacy Policy (http://goo.gl/SyrVzj) and the Chrome Privacy Policy (http://goo.gl/0uXE5d).
         </message>
         <message name="IDS_PLAY_STORE_CHANGES" desc="List of what's changed in this release of Chrome Remote Desktop for Android. [CHAR-LIMIT=500] [NAME=play_store_changes]">
-• Added support for Android 9.0 Pie.
-• Support for resizing remote desktop resolution to match your Android device's screen.
+Stability improvements and bug fixes.
         </message>
 
         <!-- iOS App Store metadata text. Won't be bundled into the app. -->
@@ -717,8 +716,7 @@ Securely access your computer from your iOS device. It's fast, simple and free.
 • On your iOS device, open the app and tap on any of your online computers to connect.
         </message>
         <message name="IDS_APP_STORE_CHANGES" desc="List of what's changed in this release of Chrome Remote Desktop for iOS. [CHAR-LIMIT=4000] [NAME=app_store_changes]">
-• Better panning and zooming experience on iPhone X.
-• Stability improvements and bug fixes.
+Stability improvements and bug fixes.
         </message>
       </if>  <!-- is_android or is_ios -->