Handle the new app source certificate

The new cert type
 - needs user authorization to install (same as CA cert)
 - does not need a name from user (same as CA cert)
 - needs to be install to keystore under its own uid (same as WiFi cert)
 - needs a reboot to be effective since it's loaded to kernel at boot
 - is only actually used when enabled on the device (not required yet)

Test: install from Settings, see the file stored in
      /data/misc/keystore/user_0
Build: 112038744

Change-Id: I56d2418069435c366f17cf346e5d1e47ba758a91
4 files changed