Push the chrome.bluetooth ChromeOS Platform App API to stable for M33.

BUG=242982
R=asargent@chromium.org

Review URL: https://codereview.chromium.org/74533002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@235851 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 235851