Add kernel permission for bootconfig proc file

Just before selinux is set up, the kernel context must be allowed to
access the /proc/bootconfig file to read the state of the
androidboot.selinux= property. Such permission was already granted for
accessing the /proc/cmdline file for the same reason.

Bug: 173815685
Test: launch_cvd -extra_kernel_cmdline androidboot.selinux=permissive
Test: launch_cvd -guest_enforce_security=false [bootconfig method]
[..]
init: Permissive SELinux boot, forcing sys.init.perf_lsm_hooks to 1.
[..]
Change-Id: I999c0c9d736bed18e5daea81bb0f8cc78350eba7
1 file changed