Add getSurfaceRotation API to MotionEvent

Add an API to get the current rotation value of the transform of the
MotionEvent.

Bug: 207771136
Test: atest MotionEventTest
Change-Id: I05fb4455d0dcfc0de8c8564473ee8d43ac86c0bd
diff --git a/include/input/Input.h b/include/input/Input.h
index 5242dcb..29503af 100644
--- a/include/input/Input.h
+++ b/include/input/Input.h
@@ -574,6 +574,8 @@
 
     inline ui::Transform getTransform() const { return mTransform; }
 
+    int getSurfaceRotation() const;
+
     inline float getXPrecision() const { return mXPrecision; }
 
     inline float getYPrecision() const { return mYPrecision; }