Update icon tint color when the user toggles Dark theme

- Reload theme in slice provider when Dark theme mode changes for slices
- Reload theme in onCreate of Panel activity for its non-slice header
- Remove applyTheme from individual slices

Test: robotest
Fixes: 153700819
Change-Id: I40a7d2817c4b9100d7b2f2962a69c8a9ce6f7906

src/com/android/settings/slices/SliceBuilderUtils.java

@@ -73,8 +73,6 @@ public class SliceBuilderUtils {
      * {@param sliceData} is an inline controller.
      */
     public static Slice buildSlice(Context context, SliceData sliceData) {
-        // Reload theme for switching dark mode on/off
-        context.getTheme().applyStyle(R.style.Theme_Settings_Home, true /* force */);
         Log.d(TAG, "Creating slice for: " + sliceData.getPreferenceController());
         final BasePreferenceController controller = getPreferenceController(context, sliceData);
         FeatureFactory.getFactory(context).getMetricsFeatureProvider()