[automerge] Move color picking code into AOSP 2p: 53fc4d5aa3 2p: d7a3eb43ca

Original change: https://googleplex-android-review.googlesource.com/c/platform/packages/apps/ThemePicker/+/16977505

Bug: 218396282
Change-Id: If7216a53bb0464ece3c80ce9abf49ba4db0a8e1b