Fix some wrong-thread issues around animator management

 Bug: 17372309

 Fixes a case where UI thread and RT thread both used the same method
 which wasn't safe for either of them.

 Adds additional assertions & logging in unusual circumstances to
 try and track down where the issue is occuring from.

Change-Id: I93d31a6fd0c5927259b67bdf96a475944226eee6
diff --git a/libs/hwui/Animator.cpp b/libs/hwui/Animator.cpp
index da65f38..4f3a573 100644
--- a/libs/hwui/Animator.cpp
+++ b/libs/hwui/Animator.cpp
@@ -161,6 +161,13 @@
     return false;
 }
 
+void BaseRenderNodeAnimator::forceEndNow(AnimationContext& context) {
+    if (mPlayState < FINISHED) {
+        mPlayState = FINISHED;
+        callOnFinishedListener(context);
+    }
+}
+
 void BaseRenderNodeAnimator::callOnFinishedListener(AnimationContext& context) {
     if (mListener.get()) {
         context.callOnFinished(this, mListener.get());