Configure existing ThemePicker Robolectric tests to run with atest.

Bug: 260777356
Bug: 260925899
Test: this is the test
Change-Id: I25c4efdb73dc5eb88611efac669de13fa2be0c3d
(cherry picked from commit 9a9c7c18096f41f07eef5f8e7350dd3edbc8b892)
Merged-In: I25c4efdb73dc5eb88611efac669de13fa2be0c3d
16 files changed