[Android] Change the settings menu a little more. Instead of the settings being a single view with settings from all components being displayed, I have broken it into sections. This future-proofs the settings menu in the sense that it won't get cluttered before people start asking "Hey, shouldn't this be broken into sections?".

As of this commit, it is broken into CPU Settings and Video Settings.
I also simplified the code that is responsible for setting the valid CPU cores and video backends by simply making UI string arrays that get chosen, based on the platform the Android device is running on.

Source/Android/res/layout/prefs.xml

@@ -1,24 +1,30 @@
 <?xml version="1.0" encoding="utf-8"?>
-<PreferenceScreen xmlns:android="http://schemas.android.com/apk/res/android"
-        >
-    <PreferenceCategory
-            android:summary="@string/settings"
-            android:title="@string/cpu_settings"
-            android:key="cpuprefcat">
+<PreferenceScreen xmlns:android="http://schemas.android.com/apk/res/android">
+    
+    <!-- CPU Settings -->
+    <PreferenceScreen
+        android:title="@string/cpu_settings">
+	            
         <CheckBoxPreference
-                android:key="dualcorepref"
-                android:summary="@string/on_off"
-                android:title="@string/dual_core" />
-    </PreferenceCategory>
-    <PreferenceCategory
-            android:summary="@string/settings"
-            android:title="@string/video_settings"
-            android:key="videoprefcat">
+               android:key="dualCorePref"
+               android:summary="@string/on_off"
+               android:title="@string/dual_core" />
+        
         <ListPreference
-                android:entries="@array/gpuOptions"
-                android:entryValues="@array/gpuValues"
-                android:key="gpupref"
-                android:summary="@string/video_backend_to_use"
-                android:title="@string/video_backend" />
-    </PreferenceCategory>
+            android:key="cpuCorePref"
+            android:summary="@string/emu_core_to_use"
+            android:title="@string/cpu_core" />
+	        
+    </PreferenceScreen>
+    
+    <!-- Video Settings -->
+    <PreferenceScreen
+        android:title="@string/video_settings">
+	        
+        <ListPreference
+               android:key="gpuPref"
+               android:summary="@string/video_backend_to_use"
+               android:title="@string/video_backend" />
+	        
+    </PreferenceScreen>
 </PreferenceScreen>