Move date/time prefs to PreferenceController and add tests.

Bug: 32996243
Test: RunSettingsRoboTests
Change-Id: Ie537bbcc35a96a63251e46f84b57c0a861b9d013

src/com/android/settings/datetime/TimeFormatPreferenceController.java

@@ -58,8 +58,7 @@ public class TimeFormatPreferenceController extends PreferenceController {
 
     @Override
     public void updateState(Preference preference) {
-        if (!(preference instanceof TwoStatePreference)
-                || !TextUtils.equals(KEY_TIME_FORMAT, preference.getKey())) {
+        if (!(preference instanceof TwoStatePreference)) {
             return;
         }
         ((TwoStatePreference) preference).setChecked(is24Hour());