recovery: Allow recovery to change the label on rfs_system_file

We can now correctly relabel files that need to be labled as
rfs_system_file. These lie under system/rfs so are not coverred
by the rule that allows recovery to relabel files under /system/bin.

CRs-Fixed: 817238
Change-Id: I8dba2463d22ed3b21c9e72f8bc74e1d457b1cb6a
1 file changed