[iOS] Update case for "Sync is on"/"Sync is off"

https://drive.google.com/open?id=1942lUZ9_kpjOzIvlrk0I9OBfYpa-pO8A
https://drive.google.com/open?id=1atZHLclvCjd3xajAuJW7GCF5N4gtaTVX

Bug: 939056
Change-Id: If9480112f5b1174ffa11de35e63f9c719d8fcd4b
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1506772Reviewed-by: Gauthier Ambard <gambard@chromium.org>
Reviewed-by: Jérôme Lebel <jlebel@chromium.org>
Commit-Queue: Gauthier Ambard <gambard@chromium.org>
Cr-Commit-Position: refs/heads/master@{#638525}

ios/chrome/app/strings/ios_strings.grd

@@ -1516,10 +1516,10 @@ Handoff must also be enabled in the General section of Settings, and your device
         Syncing to <ph name="EMAIL">$1<ex>john.doe@gmail.com</ex></ph>
       </message>
       <message name="IDS_IOS_SIGN_IN_TO_CHROME_SETTING_SYNC_OFF" desc="The subtitle for the setting item of the signed in user when sync is off [iOS only]">
-        Sync is Off
+        Sync is off
       </message>
       <message name="IDS_IOS_SIGN_IN_TO_CHROME_SETTING_SYNC_ON" desc="The subtitle for the setting item of the signed in user when sync is on [iOS only]">
-        Sync is On
+        Sync is on
       </message>
       <message name="IDS_IOS_SPOTLIGHT_KEYWORD_EIGHT" desc="Keyword used in Spotlight that will be linked to the Chrome App. [iOS only]">
         Online

ios/chrome/app/strings/ios_strings_grd/IDS_IOS_SIGN_IN_TO_CHROME_SETTING_SYNC_OFF.png.sha1

+9bfb049e5a0c6c49e6b65de93857ff11bbf737dd
\ No newline at end of file

ios/chrome/app/strings/ios_strings_grd/IDS_IOS_SIGN_IN_TO_CHROME_SETTING_SYNC_ON.png.sha1

-6bb2ae6df2d558f808f67e753b0a22bf9d9e89b0
+090f44b7e0b23ed33b5066642aeeca97540c12d6
\ No newline at end of file