restorecon /data/misc/media.

Otherwise it will be mislabeled on upgrades with existing userdata.

AOSP: https://android-review.googlesource.com/79022/

Signed-off-by: Humberto Borba <humberos@gmail.com>
Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>
Change-Id: Ibde88d5d692ead45b480bb34cfe0831baeffbf94