Sync FM app with upstream

Change-Id: I7bed8942b447d6965092dae5d50c0c9923d85bca
Fix writing to external storage

Change-Id: I1d9663de25dfa12280d3db0d868c35cd5a76dd5e
Change storage folder permissions as suggested by Google

 * mkdir /storage is already created by init.rc, so remove it here
 * Google's example has owner/group on external storage dirs set to root

Change-Id: I7980647593b2a0bf7b3553bd974a85bd75432f22