The kernel  modules under /vendor partition has been relabeled to vendor_file.
This CL allows for the modprobe to load modules labeled vendor_file.

Kernel modules are loaded in init.rc with following commands:
    exec u:r:modprobe:s0 -- /system/bin/modprobe -d /vendor/lib/modules MODULE

Bug: 35653245
Test: tested on sailfish
Change-Id: I2132ca4de01c5c60476dad8496e98266de5a1bb7

This change extends the recovery mode modprobe sepolicy
to support loadable kernel module in normal mode by using
statement below in init.rc:

exec u:r:modprobe:s0 -- /system/bin/modprobe \
    -d /vendor/lib/modules mod

Bug: b/35653245
Test: sailfish  with local built kernel and LKM enabled
Change-Id: I827e2ce387c899db3e0e179da92e79c75d61f5ae
(cherry picked from commit b638d949)

This change defines new policy for modprobe (/sbin/modprobe) that should
be used in both recovery and android mode.

Denials:
[   16.986440] c0    437 audit: type=1400 audit(6138546.943:5): avc:
denied  { read } for  pid=437 comm="modprobe" name="modules" dev="proc"
ino=4026532405 scontext=u:object_r:modprobe:s0
tcontext=u:object_r:proc:s0 tclass=file permissive=1
[   16.986521] c0    437 audit: type=1400 audit(6138546.943:6): avc:
denied  { open } for  pid=437 comm="modprobe" path="/proc/modules"
dev="proc" ino=4026532405 scontext=u:object_r:modprobe:s0
tcontext=u:object_r:proc:s0 tclass=file permissive=1
[   16.986544] c0    437 audit: type=1400 audit(6138546.943:7): avc:
denied  { getattr } for  pid=437 comm="modprobe" path="/proc/modules"
dev="proc" ino=4026532405 scontext=u:object_r:modprobe:s0
tcontext=u:object_r:proc:s0 tclass=file permissive=1

Bug: 35633646
Test: Build and tested it works in sailfish recovery. The modprobe is
invoked in init.rc (at the end of 'on init') with following command line

    exec u:r:modprobe:s0 -- /sbin/modprobe -a nilfs2 ftl

Change-Id: Ie70be6f918bea6059f806e2eb38cd48229facafa