Enable ManifestTest.AppLaunchContainer as it should be passing now.

BUG=47230
TEST=test passes
TBR=robertshield

Review URL: http://codereview.chromium.org/2844016

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@50553 0039d316-1c4b-4281-b951-d872f2087c98