Make Pip usage of FrameCallbackScheduler an actual class

Bug: 175330528
Test: Builds with new dynamic-animation library
Change-Id: I1632bd87a0f02940317a38a87b074d303f80b8c7

libs/WindowManager/Shell/src/com/android/wm/shell/pip/phone/PipMotionHelper.java

@@ -83,8 +83,18 @@ public class PipMotionHelper implements PipAppOpsListener.Callback,
 
     private ThreadLocal<AnimationHandler> mSfAnimationHandlerThreadLocal =
             ThreadLocal.withInitial(() -> {
-                FrameCallbackScheduler scheduler = runnable ->
+                final Looper initialLooper = Looper.myLooper();
+                final FrameCallbackScheduler scheduler = new FrameCallbackScheduler() {
+                    @Override
+                    public void postFrameCallback(@androidx.annotation.NonNull Runnable runnable) {
                         Choreographer.getSfInstance().postFrameCallback(t -> runnable.run());
+                    }
+
+                    @Override
+                    public boolean isCurrentThread() {
+                        return Looper.myLooper() == initialLooper;
+                    }
+                };
                 AnimationHandler handler = new AnimationHandler(scheduler);
                 return handler;
             });