Only decode to F16 if HARDWARE supports it

Bug: 123301974
Test: Infeasible

If a Bitmap is going to be decoded to F16 and then converted to
HARDWARE, only decode to F16 if HARDWARE supports it.

Previously, if we discovered after the decode that HARDWARE did not
support F16, we had to copy back to 8888 before the upload.

Change-Id: I3ceb9d053ba134bb96cfb9d638e54ac652e5db29