Fix OOM when switching between camera and camcorder.

- Camera activities extend AbstractGalleryActivity. So
  onDestroy is moved from Gallery to AbstractGalleryActivity.
- Use WeakReference for values in the WeakHashMap of
  SpinnerVisibilitySetter.

bug:5954389
Change-Id: Ib15f269bd4c54a4621bdff58e7ea16b44f8fb3e3
3 files changed