[Android] Don't create a new GCMPath entry in the Dolphin config if it another existing GCMPath entry already has the same directory path. Also, fix a 'bug' with the clear all items function. Make sure we set GCMPathes to 0, so that GCMPath entries start adding at GCMPath0 again. This change also allows me to remove the duplicate checking code from GameListFragment, since the items in the game list are loaded based on the GCMEntries in the Dolphin config.