Attempt to stop and resume playback on USB unmount/remount

Change-Id: Id44c9c5f6e17a4ce732a6fac938e00e172612b8a
Merge branch 'cm-10.1' of git://github.com/CyanogenMod/android_packages_apps_Apollo into otg-charge-usbaudio
Don't refresh metadata on remount, just update time. Media scanning is
likely not done and an attempted refresh will clear the album art, etc.

Change-Id: I1ce3682527745657f721840c13411b58bef64586