backup service: fall back to /sbin/bu

Change-Id: I46c67a401da8de92d7ef81ad40c565bb1d2ef93b
Add support for -R (recurse) to init chown builtin.

This is helpful for setting ownerships on entire directory trees,
such as sysfs and selinuxfs, particularly when the precise set of
files is dynamically generated at runtime.

Change-Id: I81070ea36fd7ffcab4ee8b3ef1bb0028d4b7839c
Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>
init: Allow basic environment variable expansion in env assignment

Allow environment variable expansion in 'export' command if the
value begins with "${_var_}" (where "${_var_}" will be replaced
with the current value of environment variable _var_).  Expansion
will only occur one time.

e.g.
export BOOTCLASSPATH ${BOOTCLASSPATH}:/system/framework/abc.jar
(cherry picked from commit 7940299507f15055851a6e8b61ae8d8a7d7f3484)

Change-Id: If9e4adfa1aba2c7a4ca243978ced3c46c2cb4d73
Fix perms on /data/security

installd and zygote need to be able
to search the directory to access
the policy files.

Change-Id: I0679fd2084d2664dfb5a594f493317eff058415d