vold: Allow ASEC containers on an external volume when internal is emulated

Thanks to Pierre-Hugues Husson for the idea in this patch! The initial
implementation called createBindMounts() on all mount points regardless
of whether or not it was the SD card.

Change-Id: Ic2c45d275179099065a10e1e664a08efea66acf1
Add SELinux restorecon calls on ASEC containers.

This will allow fine-grained labeling of the
contents of ASEC containers. Some of the contents
need to be world readable and thus should be
distinguishable in policy.

Change-Id: Iefee74214d664acd262edecbb4f981d633ff96ce
Signed-off-by: rpcraig <rpcraig@tycho.ncsc.mil>
Convert all selinux_android_restorecon and _setfilecon calls to new API.

libselinux selinux_android_restorecon API is changing to the more
general interface with flags and dropping the older variants.

Also get rid of the old, no longer used selinux_android_setfilecon API
and rename selinux_android_setfilecon2 to it as it is the only API in use.

Change-Id: I1e71ec398ccdc24cac4ec76f1b858d0f680f4925
Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>