Allow installd to restorecon /data/data.

Ability to relabel from/to any of the types that can be assigned
to /data/data directories as per seapp_contexts type= assignments.

Change-Id: I05e8b438950ddb908e46c9168ea6ee601e6d674f
Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>