Add Galaxy S4 and Nexus 4 to platform AEC whitelist.

TESTED=Good quality AEC using apprtc.

Review URL: https://codereview.chromium.org/129593002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@244117 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 244117