Android: Add a button for accessing controller mappings

The settings GameCube Controller N and Wii Remote N (where N is a number)
have two purposes: You can select what controller type you want to use,
and also, when you select a controller type (even if you're selecting the
one that already is selected), the mapping settings open. This second part
is less discoverable than it ideally should be. I'm changing it so that
there now is a button for opening the mapping settings instead.

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

@@ -478,6 +478,7 @@
     <string name="disabled">Disabled</string>
     <string name="other">Other</string>
     <string name="continue_anyway">Continue Anyway</string>
+    <string name="more_settings">More Settings</string>
 
     <!-- Game Grid Screen-->
     <string name="platform_gamecube">GameCube Games</string>