[ios] Fix settings switch accessibility value and hint

ios/chrome/app/strings/ios_strings.grd

 <?xml version="1.0" encoding="UTF-8"?>
 
 <!--
 This file contains definition of resources that will be translated for each
 locale.  The strings in this file are specific to iOS.
 -->
 
 <grit base_dir="." latest_public_release="0" current_release="1"
       output_all_resource_defines="false" source_lang_id="en" enc_check="möl">
   <outputs>
@@ skipping 1179 matching lines @@
       </message>
       <message name="IDS_IOS_SETTINGS_TITLE" desc="Title for the settings panel [iOS].">
         Settings
       </message>
       <message name="IDS_IOS_SETTING_OFF" desc="Generic status label displayed in Settings to show that a setting is currently turned off. [Length: 5em] [iOS only]">
         Off
       </message>
       <message name="IDS_IOS_SETTING_ON" desc="Generic status label displayed in Settings to show that a setting is currently turned on. [Length: 5em] [iOS only]">
         On
       </message>
+      <message name="IDS_IOS_TOGGLE_SETTING_SWITCH_ACCESSIBILITY_HINT" desc="Action hint for any switch in settings. This is spoken by VoiceOver. [iOS only]">
+        Double tap to toggle setting

[edchin, 2017/01/12 22:13:45]

The guidelines suggest not to mention 'tap': "Don’t repeat the action type in
the hint. For example, do not create hints such as “Tap to play the song” or
“Tapping plays the song.”
https://developer.apple.com/reference/objectivec/nsobject/1615093-accessibili...

[sczs, 2017/01/12 22:26:17]

I think the difference is that this is a switch, so its not something that you
would tap intuitively. On the other hand no action type is being repeated, Voice
Over will read: "Cell Text, ON/OFF.... Double tap to toggle setting" which is
the exact same hint that iOS switch settings use. 

[edchin, 2017/01/12 22:37:54]

Acknowledged.

[lpromero, 2017/01/13 10:01:33]

No action needed: I wanted to follow Apple's example in the Settings app, where
they use "Double tap to toggle setting". Note that they don't add the Button
trait to the cell, so it might be less redundant.

+      </message>
       <message name="IDS_IOS_SHARE_EMAIL_COMPLETE" desc="Message shown when email share has been sent. [Length: Unknown. Keep it short.] [iOS only]">
         Mail sent.
       </message>
       <message name="IDS_IOS_SHARE_FACEBOOK_COMPLETE" desc="Message shown when Facebook share has been posted. [Length: Unknown. Keep it short.] [iOS only]">
         Facebook post completed.
       </message>
       <message name="IDS_IOS_SHARE_GPLUS_COMPLETE" desc="Message shown when Google+ share has been posted. [Length: Unknown. Keep it short.] [iOS only]">
         Google+ post completed.
       </message>
       <message name="IDS_IOS_SHARE_MENU_PRINT_ACTION" desc="The text label of the Print action in the extension menu that starts the printing process. [Length: 13em] [iOS only]">
@@ skipping 329 matching lines @@
       </message>
       <message name="IDS_IOS_VOICE_SEARCH_SETTING_TITLE" desc="The title for Voice Search setting [Length: 29em] [iOS only]">
         Voice Search
       </message>
       <message name="IDS_IOS_VOICE_SEARCH_SETTING_TTS" desc="The label for setting switch enabling text-to-speech response after voice search [Length: 29em] [iOS only]">
         Speak Answers Back
       </message>
     </messages>
   </release>
 </grit>