The code to find the matching entry was scanning through a
list of all rules for every rule. This became extremely slow
as the number of rules became large, leading to long delays
waiting for firewall rules to be applied.
This patch switches to the use of a dictionary so the cost
becomes a hash lookup instead of a list scan.
Closes-Bug: #1453264
Closes-Bug: #1455675
Change-Id: I1e6fe5e50b9c13066c966c252cadc8ed1d08f686
7a3934d982