Add floating action button to GameGridActivity.

Source/Android/app/src/main/res/drawable/oval_ripple_gc.xml

@@ -1,9 +1,8 @@
-<!-- res/drawable/oval_ripple.xml -->
 <ripple xmlns:android="http://schemas.android.com/apk/res/android"
         android:color="?android:colorControlHighlight">
     <item>
         <shape android:shape="oval">
-            <solid android:color="@color/dolphin_wii"/>
+            <solid android:color="@color/dolphin_gamecube_accent"/>
         </shape>
     </item>
 </ripple>

Source/Android/app/src/main/res/drawable/oval_ripple_wii.xml

@@ -0,0 +1,8 @@
+<ripple xmlns:android="http://schemas.android.com/apk/res/android"
+        android:color="?android:colorControlHighlight">
+    <item>
+        <shape android:shape="oval">
+            <solid android:color="@color/dolphin_wii_accent"/>
+        </shape>
+    </item>
+</ripple>