am cb2d8817: am 2458f2a1: cherrypick Change-Id: I60c74919ab3df359f47e5052bcc1469318a5b821 add notice about large screen devices and the "mobile" string in user agent

* commit 'cb2d88176565a199ad6c6a3a6360a166bd700579':
  cherrypick Change-Id: I60c74919ab3df359f47e5052bcc1469318a5b821 add notice about large screen devices and the "mobile" string in user agent