Do not output string-encoded MotionEvent.

JsonUtils knows how to output MotionEvents into json; that mechanism
should be reused for SuddenJumpingTouchEventHandler.

Change-Id: Id4c36c05533a3a329bf43ba33d57c0830dc4d196

java/src/com/android/inputmethod/research/ResearchLogger.java

@@ -1760,7 +1760,7 @@ public class ResearchLogger implements SharedPreferences.OnSharedPreferenceChang
     public static void suddenJumpingTouchEventHandler_onTouchEvent(final MotionEvent me) {
         if (me != null) {
             getInstance().enqueueEvent(LOGSTATEMENT_SUDDENJUMPINGTOUCHEVENTHANDLER_ONTOUCHEVENT,
-                    me.toString());
+                    MotionEvent.obtain(me));
         }
     }