selftests: net: Add test for enablement of ports with teamd

selftests: net: Add test for enablement of ports with teamd

There are no tests that verify enablement and disablement of team driver
ports with teamd. This should work even with changes to the enablement
option, so it is important to test.

This test sets up an active-backup network configuration across two
network namespaces, and tries to send traffic while changing which
link is the active one.

Also increase the team test timeout to 300 seconds, because gracefully
killing teamd can take 30 seconds for each instance.

Signed-off-by: Marc Harvey <marcharvey@google.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com>
Link: https://patch.msgid.link/20260409-teaming-driver-internal-v7-5-f47e7589685d@google.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>