Gallery2: Fix batches of issues in movie effects

Fix following issues:
- All settings aren't restored to previous state when user cancel
his operations.
- Check the validity to avoid calling member function of an already
released object.
- Recycle effect instance when MovieActivity pauses.
- Don't restore strength from pref when toggling switch.
- Force the Effect's dialog to be uncancelable.
- Fix null pointer and effect leak issue due to CMCC features.
- Fix audio effects dialog display on small screens.
- Recognize bluetooth headset.
- Update visual design.

Conflicts:
	src/com/android/gallery3d/ui/Knob.java

Change-Id: I803897508c0c1a6723170b7691e3ece03680e4f1