Add redundant tint to notification and footer button backgrounds.

This is required because Resources apparently isn't thread-safe, and can end up with an inconsistent cache, especially for drawables, for an extended period after a theme change.

Tracking the removal of this duplicate code with:
Bug: 282173943

Fixes: 282168337
Test: toggle night mode until the bug hits (detectable by logging in I4879dd28a8d88b3ee6fc1f09c9029eb653bfa460) then verify the notifications still look right.
Change-Id: Ie5e0d7144f4851bdb82f18ffdda2c910ee0790ef