selftests: tc: act_pedit: require matching IPv4 L4 protocol

selftests: tc: act_pedit: require matching IPv4 L4 protocol

Add a tdc test that checks the act_pedit extended L4 header mode does not
edit a packet whose IPv4 protocol does not match the selected transport
header.

The test installs an ingress pedit rule that sets the UDP destination
port, then injects a TCP packet with dport 2222. The UDP and TCP
destination ports sit at the same L4 offset, so a buggy kernel rewrites
the TCP dport. A second flower filter matches TCP dport 2222 and drops
the packet through an indexed gact action; the test then verifies via
JSON that this action saw exactly one packet, i.e. the dport was left
untouched and still matched 2222.

Signed-off-by: Victor Nogueira <victor@mojatatu.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>