ExternalStorageProvider: use mount point in device list

For me its is extremely unlogical that only the volume label is used
in the device list. Even more because it can be an empty string
and for a normal android user this information is not visible
anywhere else.

Using the mount point and if available the device label
separated by "-" makes much more sense and shows the same
information as all other apps that access external storage

Change-Id: I3fc3675af6640e37aa999b03ae2de2858237c638
[1/3] Base: Flip to Mute/Reject Call

Saving flip action value to settings container

Telephony: https://gerrit.omnirom.org/#/c/4670/
InCallUI: https://gerrit.omnirom.org/#/c/4669/

Change-Id: Ie72dda49d78b23b9bc7d8a886f6916f678c918d1
Merge "ExternalStorageProvider: use mount point in device list" into android-4.4
Merge "[1/3] Base: Flip to Mute/Reject Call" into android-4.4
Merge remote-tracking branch 'omni/android-4.4' into android-4.4