m3: guard wear material3 UI change for Button

The change in base widget has very broad impact, therefore, the change
should be guarded with following conditions:
1. app target sdk is 36 or above.
2. feature flag rolled-out.
3. device is a watch.

Bug: 376561342
Test: manual
Flag: android.widget.flags.use_wear_material3_ui
Change-Id: I50f91d16187c2c687da1e66668f094b9983f021f