Added zen settings messages and calls preferences.

- Made ZenModeSettings and ZenModeBehaviorSettings a DashboardFragment
- Switches in ZenModeBehaviorSettings all have their own preference controllers
- Instead of a dropdown, messages & calls have their own pages & preference controllers
- Added basic turn on/off DND button in settings (dialog not yet implemented)

Bug: 63077372
Fixes: 69057767
Test: make -j40 RunSettingsRoboTests
Change-Id: I1c70f77053713f66f873ee578477f23cfd7985bb

tests/robotests/src/com/android/settings/notification/ZenModeScheduleRuleSettingsTest.java

@@ -105,11 +105,6 @@ public class ZenModeScheduleRuleSettingsTest {
         protected Object getSystemService(final String name) {
             return null;
         }
-
-        @Override
-        protected void maybeRefreshRules(boolean success, boolean fireChanged) {
-            //do nothing
-        }
     }
 
 }