Temporarily allow programmatic input assistance for adding Gmail account

Temporarily allow programmatic input assistance for adding Gmail account
https://bugs.webkit.org/show_bug.cgi?id=147792

Reviewed by Enrica Casucci.
<rdar://problem/22126518>

Temporary fix for keyboard input sliding out and immediately back in upon user interaction
in the Gmail 2-factor authentication page.

Source/WebCore:

* platform/RuntimeApplicationChecksIOS.h:
* platform/RuntimeApplicationChecksIOS.mm:
(WebCore::applicationIsGmailAddAccountOnIOS): Added bundle ID for Gmail settings.

Source/WebKit2:

* UIProcess/ios/WKContentViewInteraction.mm:
(-[WKContentView _startAssistingNode:userIsInteracting:blurPreviousNode:userObject:]): Early
    return no longer triggers due to lack of user interaction when adding a new Gmail account
    through Settings.

git-svn-id: https://svn.webkit.org/repository/webkit/trunk@188162 268f45cc-cd09-0410-ab3c-d52691b4dbfc