move paint color to Params
move paint color to Params

Not really sure why it's still in BlitterUniforms when it doesn't change
from blit to blit... it's really more like the paint SkFilterQuality.

The only real caveat is that we need to take care to push the same
uniforms in cache_key() and build_program(), in particular making sure
we reuse the paint color uniforms if there's a clip shader.

Change-Id: I4c82b43b72b2a64341568f49f2f6dabad17fbc3e
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/319767
Reviewed-by: Mike Klein <14574f09dfa9b4e14759b88c3426a495a0e627b0@google.com>
Commit-Queue: Mike Klein <14574f09dfa9b4e14759b88c3426a495a0e627b0@google.com>

aosp-mirror/platform_external_skia,aosp-mirror/platform_external_skia,google/skia,google/skia,google/skia,aosp-mirror/platform_external_skia,google/skia,google/skia,aosp-mirror/platform_external_skia,google/skia,aosp-mirror/platform_external_skia,aosp-mirror/platform_external_skia,google/skia,aosp-mirror/platform_external_skia,google/skia,google/skia,aosp-mirror/platform_external_skia,aosp-mirror/platform_external_skia,aosp-mirror/platform_external_skia,google/skia