Added Opacity settings for touchscreen controls

Added Opacity controls for the user to customize the opacity of their touchscreen controls. Also, placed both Scale and Opacity settings into one window/option called Adjust Controls.

Source/Android/app/src/main/res/values/strings.xml

@@ -396,6 +396,8 @@ It can efficiently compress both junk data and encrypted Wii data.
     <string name="emulation_toggle_controls">Toggle Controls</string>
     <string name="emulation_toggle_all">Toggle All</string>
     <string name="emulation_control_scale">Adjust Scale</string>
+    <string name="emulation_control_opacity">Adjust Opacity</string>
+    <string name="emulation_control_adjustments">Adjust Controls</string>
     <string name="emulation_control_joystick_rel_center">Relative Stick Center</string>
     <string name="emulation_control_rumble">Rumble</string>
     <string name="emulation_choose_controller">Choose Controller</string>