GLES1: Fix material color update when COLOR_MATERIAL According to the spec, when COLOR_MATERIAL is enabled, the material ambient and diffuse colors are updated on every glClear* call. Additionally, setting these values individually is ineffective when COLOR_MATERIAL is enabled. Bug: angleproject:6201 Change-Id: I846513c983254a043ea83101c0f83025c12b4364 Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/3906392 Reviewed-by: Cody Northrop <cnorthrop@google.com> Commit-Queue: Shahbaz Youssefi <syoussefi@chromium.org>