Merge branch 'fix/touch' into improvements

* fix/touch:
  Change input source of Flutter touch events so they get handled by Unity.

android/src/main/java/com/rexraphael/flutterunitywidget/UnityView.java

@@ -2,6 +2,8 @@ package com.rexraphael.flutterunitywidget;
 
 import android.content.Context;
 import android.content.res.Configuration;
+import android.view.InputDevice;
+import android.view.MotionEvent;
 import android.widget.FrameLayout;
 
 import com.unity3d.player.UnityPlayer;
@@ -35,6 +37,13 @@ public class UnityView extends FrameLayout {
         }
     }
 
+    @Override
+    public boolean dispatchTouchEvent(MotionEvent ev) {
+        ev.setSource(InputDevice.SOURCE_TOUCHSCREEN);
+        view.injectEvent(ev);
+        return super.dispatchTouchEvent(ev);
+    }
+
     @Override
     protected void onDetachedFromWindow() {
         // todo: fix more than one unity view, don't add to background.