[Android] Fix some redundancy in the category names for the settings menu. In a menu named "Settings" (which is shown in the top left) we have the categories, "CPU Settings" and "Video Settings" - but the fact they are settings pages is already established at this point so it's redundant. Just made them "CPU" and "Video" instead. Also changed the description for dual-core They now look like this: http://i.imgur.com/qieaKmL.png