bump tethering tc prio to make room for rate limiting

There is currently a priority gap at 3. We need to bump tethering prios
to 2 and 3 to make room for rate limiting, which should have the top
priority.

Test: m
Bug: 157552970
Change-Id: I6e1087b232a8235e5cd42953470c72e2ae643bdc
1 file changed