Fix themed settings icons.

- Added android prefix for homeAsUpIndicator attribute
- Override ic_arrow_down_24dp from androidx
- Remove ic_lock drawable overlay
- Update date and time icon
- Dedupe ic_menu_add and ic_add_24dp

Bug: 131346125
Test: mp settings;
Change-Id: I7223249f2adccc5569a37e8b68cae5499e7c7620

src/com/android/settings/network/ApnSettings.java

@@ -351,7 +351,7 @@ public class ApnSettings extends RestrictedSettingsFragment
             if (mAllowAddingApns) {
                 menu.add(0, MENU_NEW, 0,
                         getResources().getString(R.string.menu_new))
-                        .setIcon(R.drawable.ic_menu_add)
+                        .setIcon(R.drawable.ic_add_24dp)
                         .setShowAsAction(MenuItem.SHOW_AS_ACTION_IF_ROOM);
             }
             menu.add(0, MENU_RESTORE, 0,