[SRU C/D/U] UBUNTU: [Config]: Reenable runtime tests, mainly TEST_BPF

[Thadeu Lima de Souza Cascardo]

BugLink: https://bugs.launchpad.net/bugs/1813955

We noticed that test_bpf module was not loaded anymore under the network
selftests, making disco ADT fail. Cosmic had been doing fine, because we didn't
catch these failures before.

After that, we noticed those configuration options under Runtime tests being
dropped, as the commit messages explain.

Cascardo.