Avoid setting color space agnostic when in HDR mode.

HDR is assumed to have high brightness, and thus the white means 10000 nits
when in HDR 10. Making layers color space agnostic could probably results in
wrong visual perception.

BUG: 126616348
Test: Build, flash and boot. Verify with Youtube HDR.
Change-Id: Icf6ae321cf53f31426362df2a972a0b396501f9f