[RenderScript] Utility functions to generate random Float16 Allocations.

http://b/23536224

The numbers are randomly generated in the range [MIN_NORMAL, 16.0].  To
include negative numbers, about half of the generated numbers are
negated.

Some special Float16 values are also substituted randomly.  Extreme
values are included when corresponding parameter is set.

Change-Id: I827bea2945387ccdac4704bb5ba1db978cab2d05
2 files changed