Add clamping in half_btf()
Add clamping in half_btf()

BUG=69073461

Change-Id: Ib28b41adfa2738681357903a81a89bcab01c87b3
(cherry picked from commit 08b26a8a257e54210d8bbdba799980bc291f368e)

GrokImageCompression/aom,GrokImageCompression/aom,GrokImageCompression/aom,GrokImageCompression/aom,GrokImageCompression/aom,GrokImageCompression/aom