m3: wear material3 button style can only override DeviceDefault theme

Platform Wear Material3 should only override Theme.DeviceDefault
instead of dicatating all themes.

Flag: android.widget.flags.use_wear_material3_ui
Test: manual & cts
Bug: 376561342
Bug: 380281547
Bug: 380312688
Change-Id: Ibbe9b754887eb478dd51752ec24bec75ac5f0853