snapuserd: Add selinux policy

Add selinux policy to allow snapuserd to search
through /dev/block/ and read /sys/block directory.

Bug: 193863442
Test: OTA on pixel
Signed-off-by: Akilesh Kailash <akailash@google.com>
Change-Id: I656aee69f4c07ed7caeb1c3c14e44e1a25bd1ba1
1 file changed