Capture orientation and screen size config changes

This is to prevent the About dialog from
disappearing on the MainActivity when the screen
is rotated.

Author: brarcher

app/src/main/AndroidManifest.xml

@@ -15,6 +15,7 @@
         <activity
             android:name=".MainActivity"
             android:label="@string/app_name"
+            android:configChanges="orientation|screenSize"
             android:theme="@style/AppTheme.NoActionBar">
             <intent-filter>
                 <action android:name="android.intent.action.MAIN" />