Add @HalfFloat annotation to mark fp16 values stored in shorts

Half-precision float values can be converted to/from floats using
android.util.Half. Half-precision floats are stored in shorts which
makes this annotation useful to distinguish between regular shorts
and shorts that hold fp16 values.

Test: source level annotation only
Bug: 29940137
Change-Id: I1982d2ca6a3a17289af7853410f4e74344eaa7f6
1 file changed