Update engine is responsible for updating various partitions, which
includes enabling or disabling the read-only bit on the underlying block
device.

Rather than try to list out each block device separately, generalize the
ioctl rules to apply to all block device nodes. If the ioctl permission
is granted via a normal allow rule, then the allowxperm statement will
allow BLKROGET and BLKROSET by default on those block devices.

Test: policy compiles
Bug: 118150702
Change-Id: I7bca52e0f442df7320748f6d6371e5016aa6dd0b