Zen automatic rule page ui changes

- Can change rule name from header
- Text for turning on/off rule is now "Use rule" instead of on/off

Test: make ROBOTEST_FILTER=EntityHeaderControllerTest RunSettingsRoboTests -j40
Test: manual (Settings > Sound > Do Not Disturb > Turn On Automatically)
Bug: 63077372
Change-Id: Id55b02de0509f168c2470a4f875e84140eb840fa