Remove CameraUtil.launchGallery, ensure SecureCamera uses Gallery up icon

Remove CameraUtil.launchGallery, ensure SecureCamera uses Gallery up icon

CameraUtil.launchGallery incorrectly describes a mechanism to call an APP_GALLERY
category intent. Since we're using Gallery icon we should go direct to Gallery,
which IntentHelper already does. Simply removed the util class and call the
helper direct from the activity. Also noticed during testing that the SecureCamera
was not correctly showing the Gallery icon, though its behavior would take user
to Gallery. Finally, removing restriction that the video player intent should
go to Gallery, instead it should route to system preferred intent.

Bug: 11065256
Change-Id: I941f9469de169919c4bac6c91dde7e577921f737