sepolicy: FST fixes

1. Restore access to hostapd global socket from fstman.
2. fstman now generates its configuration (fstman.ini) based
on system properties, so it needs read access to these.
3. wpa_supplicant global socket moved to vendor_wpa_wlan0,
so fstman (and other vendor services) can access it.

Change-Id: I099d7f3b187989c26666b93288b1693f5db20bec