This commit introduces a verification step that runs before APF
offload tests.
It uses the `cmd network_stack apf <iface> config` shell command
to dump the list of enabled offloads. By checking this list first,
we can ensure that the specific offload under test is actually
enabled, avoiding misleading failures and improving test reliability.
Flag: EXEMPT mainline
Bug: 419427388
Test: ./cts-tradefed run commandAndExit cts -m CtsConnectivityMultiDevicesTestCases -t ApfV6Test --shard-count 2
Test: atest CtsConnectivityMultiDevicesTestCases:ApfV6Test
Change-Id: I65fecdcd4f2f9e9586da2684bf68cec215d0f359