Fix 3-Button Color w/ Widget Sheet post-Rotation

Fixed issue where upon opening the widgets menu in the home screen in landscape, then rotating screen to portrait, then back to landscape (whilst keeping widget sheet open), the buttons are dim colored rather than white.

Flag: NONE
Test: Manually tested in pixel 7 in light mode and dark mode (with home screen rotation enabled).
Bug: 284801356
Change-Id: I0ed59373eb3af5f1b5ab695b43b850777042d2eb