Merge "Make sure we start new activity only in UI thread." into tm-qpr-dev am: fd2471b990

Original change: https://googleplex-android-review.googlesource.com/c/platform/packages/apps/Launcher3/+/21484427

Change-Id: I851ac58eb0dafa863bbf6efb6e19299d04ae3e2e
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>

src/com/android/launcher3/views/ActivityContext.java

@@ -313,7 +313,7 @@ public interface ActivityContext {
      */
     default boolean startActivitySafely(
             View v, Intent intent, @Nullable ItemInfo item) {
-
+        Preconditions.assertUIThread();
         Context context = (Context) this;
         if (isAppBlockedForSafeMode() && !PackageManagerHelper.isSystemApp(context, intent)) {
             Toast.makeText(context, R.string.safemode_shortcut_error, Toast.LENGTH_SHORT).show();