sepolicy: Allow recovery to read to all sdcard filesystems

avc: denied  { open } for  pid=355 comm="recovery" path="/storage/FB77-9A59" dev="mmcblk0p1" ino=1 scontext=u:r:recovery:s0 tcontext=u:object_r:exfat:s0 tclass=dir permissive=0

Change-Id: If991762285e348c1911daf2c80aa028613ae6f54