Fix Touch not working on some Google Pixel phones

templates/android/template/app/src/main/java/org/libsdl/app/SDLActivity.java

@@ -1933,13 +1933,23 @@ class SDLSurface extends SurfaceView implements SurfaceHolder.Callback,
     @Override
     public boolean onTouch(View v, MotionEvent event) {
         /* Ref: http://developer.android.com/training/gestures/multi.html */
-        final int touchDevId = event.getDeviceId();
+        int touchDevId = event.getDeviceId();
         final int pointerCount = event.getPointerCount();
         int action = event.getActionMasked();
         int pointerFingerId;
         int mouseButton;
         int i = -1;
         float x,y,p;
+		
+		/**
+		* Prevent id to be -1, since it's used in SDL internal for synthetic events
+		* Appears when using Android emulator, eg:
+		*  adb shell input mouse tap 100 100
+		*  adb shell input touchscreen tap 100 100
+		*/
+		if (touchDevId < 0) {
+			touchDevId -= 1;
+		}
 
         // 12290 = Samsung DeX mode desktop mouse
         // 12290 = 0x3002 = 0x2002 | 0x1002 = SOURCE_MOUSE | SOURCE_TOUCHSCREEN