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-zh-rCN/strings.xml

@@ -205,6 +205,10 @@
 	
     <string name="title_enable_perf_overlay"> 启用性能信息 </string>
     <string name="summary_enable_perf_overlay"> 在串流中显示实时性能信息 </string>
+    <string name="title_osc_opacity">更改屏幕按钮透明度</string>
+    <string name="dialog_title_osc_opacity">透明度</string>
+    <string name="suffix_osc_opacity">%</string>
+    <string name="summary_osc_opacity">令屏幕按钮变得更透明/更不透明</string>
 
 
 </resources>