Send HWUI load reset hint when Choreographer registers a callback

Send a load reset hint hint to DrawFrameTask through ThreadedRenderer
from ViewRootImpl whenever Choreographer registers a callback. This
allows the PowerHAL to allocate more resources for HWUI in response to
upcoming work, helping prevent frame drop.

Bug: b/243938267
Test: manual

Change-Id: Ie2cf809cf85530af04f4d0db3407853d4da03d62
diff --git a/libs/hwui/renderthread/RenderProxy.h b/libs/hwui/renderthread/RenderProxy.h
index 2a99a73..a21faa8 100644
--- a/libs/hwui/renderthread/RenderProxy.h
+++ b/libs/hwui/renderthread/RenderProxy.h
@@ -109,6 +109,7 @@
     static int maxTextureSize();
     void stopDrawing();
     void notifyFramePending();
+    void notifyCallbackPending();
 
     void dumpProfileInfo(int fd, int dumpFlags);
     // Not exported, only used for testing