[iOS] Accessibility label for Discover feed header menu button

Accessibility label for the gear button in the NTP's Discover feed
header. Uses the same text as Clank.

Bug: 1085419
Change-Id: I9522aa1b5a9c13bb6c4ebbb2a757e4088beec440
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2359736Reviewed-by: Sergio Collazos <sczs@chromium.org>
Commit-Queue: Adam Trudeau-Arcaro <adamta@google.com>
Cr-Commit-Position: refs/heads/master@{#798748}

ios/chrome/app/strings/ios_strings.grd

@@ -738,6 +738,9 @@ Because your account is managed by <ph name="HOSTED_DOMAIN">$1<ex>google.com</ex
       <message name="IDS_IOS_DISCOVER_FEED_MENU_TURN_ON_ITEM" desc="The 'Turn On' action for the Discover feed header menu.">
         Turn On
       </message>
+      <message name="IDS_IOS_DISCOVER_FEED_MENU_ACCESSIBILITY_LABEL" desc="The accessibility label for the Discover feed header's menu button.">
+        Options for Discover
+      </message>
       <message name="IDS_IOS_DOWNLOAD_MANAGER_CANNOT_DETERMINE_FILE_SIZE" desc="Message displayed when the size of the file to be downloaded is unknown. [Length: 30em] [iOS only]">
         Cannot determine file size.
       </message>

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

+276fc0af72ecdf35710046b80eb3609b0498bd23
\ No newline at end of file

ios/chrome/browser/ui/content_suggestions/cells/content_suggestions_discover_header_item.mm

@@ -103,6 +103,8 @@ const CGFloat kHeaderBorderRadius = 8;
     _menuButton.translatesAutoresizingMaskIntoConstraints = NO;
     _menuButton.accessibilityIdentifier =
         kContentSuggestionsDiscoverHeaderButtonIdentifier;
+    _menuButton.accessibilityLabel =
+        l10n_util::GetNSString(IDS_IOS_DISCOVER_FEED_MENU_ACCESSIBILITY_LABEL);
     [_menuButton
         setImage:[[UIImage imageNamed:@"infobar_settings_icon"]
                      imageWithRenderingMode:UIImageRenderingModeAlwaysTemplate]