fix broken ColorBufferTest

- Two errors were happening:
1. wrong pixel : caused by wrong read postion (w/2, w/2) instead of (w/2, h/2)
2. null view when onPause is called
- also clean-up some style issues, but not all.

Bug: 6952768
Change-Id: Id1a493e691b23fa315b19b6eb19e33edc61c518a