Make installd run with fewer privileges. This will help make
exploitation of installd based vulnerabilities more difficult
to perform.
installd now runs with the following privileges:
* CAP_DAC_OVERRIDE
* CAP_CHOWN
These two capabilities are needed to add and remove files
from application's home directories.
* CAP_SETUID
* CAP_SETGID
These permissions are needed to further drop privileges when
running dexopt as the application UID.
"installd" no longer runs with full root privileges. It cannot,
for example, mount and unmount filesystems, install modules,
perform direct I/O, etc.
Change-Id: Ib407e41e5e4c95f35a5c6a154812c5e8ae3006ed
812b19a425