Fix app for build 7 update; added UI support for adjusting grid size

- Build 7 update broke the controllers because I did not include the "android.hardware.vr.headtracking" uses-feature in the manifest. Because of this, the headset was incorrectly registered as an Oculus Go. Looks like they started to enforce this setting in the latest update.
- Added support for adjusting the grid size in the settings panel.

Assets/Plugins/Android/AndroidManifest.xml

@@ -8,12 +8,7 @@
             <action android:name="android.intent.action.MAIN" />
             <category android:name="android.intent.category.LAUNCHER" />
         </intent-filter>
-        <!--<intent-filter>
-            <data android:scheme="questapplauncher" />
-            <action android:name="android.intent.action.VIEW" />
-            <category android:name="android.intent.category.DEFAULT" />
-            <category android:name="android.intent.category.BROWSABLE" />
-        </intent-filter>-->
     </activity>
   </application>
+  <uses-feature android:name="android.hardware.vr.headtracking" android:required="true" android:version="1" />
 </manifest>