Update policy for Android 4.2 / latest master.
Primarily this consists of changes around the bluetooth subsystem.
The zygote also needs further permissions to set up /storage/emulated.
adbd service now gets a socket under /dev/socket.
keystore uses the binder.

Change-Id: I8c5aeb8d100313c75169734a0fa614aa974b3bfc
Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>

Allow reading of properties area, which is now created before init has switched contexts.  Revisit this later - we should explicitly label the properties file.