Add opacity settings to on-screen controls (#798)

* Restore resize controls, Make buttons oval

* Create new default configuration

* Split Configuration Mode into separate Move and Resize modes

* Add transparency setting for on-screen buttons

* Updated translations for on-screen controls

Co-authored-by: Leo <chun.huang@student.manchester.ac.uk>

app/src/main/res/values-it/strings.xml

@@ -159,5 +159,6 @@
     <string name="summary_video_format">H.265 riduce i requisiti di larghezza di banda video ma richiede un dispositivo molto recente</string>
     <string name="title_enable_hdr">Abilita HDR (sperimentale)</string>
     <string name="summary_enable_hdr">Utilizza l\'HDR quando il gioco e la scheda video del PC lo supportano. L\'HDR richiede una scheda video serie GTX 1000 o sucessive.</string>
-	
+    <string name="suffix_osc_opacity">%</string>
+
 </resources>