Tweaked constants for Gcam.

Bug: 17629128
Bug: 17550818

- In HDR+ mode only, change tap-to-expose/focus rectangle to 12% of the
  viewfinder - works much better and matches final output.
- Changed post-shot return-to-continuous-AF constant to 1 second (3 seconds was
  too long).

Submit together with ag/554414.

Change-Id: I56afb19e4378dbfa25f38376b05293fdb3908d47
2 files changed