Defer recreation until resumed

- Temporarily work around issue with activity recreation while started
  but not resumed by deferring recreating the activity on theme
  change until after launcher has resumed.

Bug: 162812884
Test: Switch dark mode via QuickSettings, Settings
Test: Change system theme
Change-Id: Ifbc0d538907a30d6b23176cd67353a81b6f8c617

src/com/android/launcher3/BaseDraggingActivity.java

@@ -42,6 +42,7 @@ import android.widget.Toast;
 
 import androidx.annotation.Nullable;
 
+import com.android.launcher3.Launcher.OnResumeCallback;
 import com.android.launcher3.LauncherSettings.Favorites;
 import com.android.launcher3.logging.InstanceId;
 import com.android.launcher3.logging.InstanceIdSequence;
@@ -108,10 +109,20 @@ public abstract class BaseDraggingActivity extends BaseActivity
 
     private void updateTheme() {
         if (mThemeRes != Themes.getActivityThemeRes(this)) {
-            recreate();
+            // Workaround (b/162812884): The system currently doesn't allow recreating an activity
+            // when it is not resumed, in such a case defer recreation until it is possible
+            if (hasBeenResumed()) {
+                recreate();
+            } else {
+                addOnResumeCallback(this::recreate);
+            }
         }
     }
 
+    protected void addOnResumeCallback(OnResumeCallback callback) {
+        // To be overridden
+    }
+
     @Override
     public void onActionModeStarted(ActionMode mode) {
         super.onActionModeStarted(mode);

src/com/android/launcher3/Launcher.java

@@ -1943,6 +1943,7 @@ public class Launcher extends StatefulActivity<LauncherState> implements Launche
         return result;
     }
 
+    @Override
     public void addOnResumeCallback(OnResumeCallback callback) {
         mOnResumeCallbacks.add(callback);
     }