Change access of some variables to enable blur for 3D effect

Change some private variables to protected for ImageEffectPreviewFragment.

Bug: 234085595
Test: Manual
Change-Id: I0ae2e322f0038ea9051dd4a10f9a6501cd9cda29
Merged-In: I0ae2e322f0038ea9051dd4a10f9a6501cd9cda29
1 file changed