VideoModule: check for videosnapshot support in onSingleTapUp

onSingleTapUp is now triggered through PreviewGestures instead of
ActivityBase, so the check in initializeVideoSnapshot() is no
longer enough to prevent triggering video snapshot on unsupported
devices.

Change-Id: I5f6e14f1125a9d47e03bb35fdc4ff358c589b73e
Gallery2: merge CyanogenMod

Change-Id: Ic3817de43989551fce5f2d9ecc96743fe0f31f9f