[Lut shader] in Adaptive mode, GPU path outputs gamma 2p2 encoding for

HDR layer.

Relnote: apply a gamma2.2 compensation when a gamma_oetf dimming stage
is used.

Bug: 380894872
Test: builds
Flag: EXEMPT no flag needed

Change-Id: I048d370725a7f78732689b3fef674772a874e0f3