gralloc: Default flexible YUV format to NV21

There could be buffers allocated in flexible YUV format that do
not have any camera usage flags. Default such buffers to NV21.

Bug: 21880984
Change-Id: Ieb659c05d0a69db815e6a3a0b1b574a746b3dc90
1 file changed
tree: 32d203fb6b68897f2425dc4bbaccf057dec2f4c6
  1. msm8084/
  2. msm8226/
  3. msm8960/
  4. msm8974/
  5. msm8994/
  6. Android.mk