Don't require permissions for high-priority oif rules.

The intent of the high-priority oif rules added in ag/644462 was
to ensure that the kernel can send packets and forward packets to
a given interface by specifying only the oif. However, if a
network requires permissions, the high-priority oif rules we
create require those permission bits in the firewall mark, which
means the kernel cannot use them.

Therefore, remove the permissions check.

Test: builds
Test: netd_{unit,integration}_test pass
Change-Id: I73d7eb349c4c20d0d5efe05219a89cff5015a330