Revert "Add API to specify background color for animations"

This reverts commit 2ccc829e71dca5af5eba565319911a53499e99ef.

Reason for revert: No longer needed

Test: Existing tests
Bug: 200763116
Change-Id: Ibd9f22af05eba99c4509b503665c1e915993c940
5 files changed