Changes

testenv: requirements: find programs in /usr/sbin

Fix that testenv complains about a missing setcap program, if it is in
/usr/sbin/setcap and /usr/sbin is not in PATH as it is the case with
Debian. We actually run setcap with sudo when it is needed, and in that
case /usr/sbin gets added to PATH in Debian.

Fix for:
  [testenv] Missing program: setcap

Change-Id: Ibbccba013ac38415ef46467f97bef846b848cf39

testenv: podman: remove mongodb-org.list

Remove mongodb-org.list at the end of building the podman image, as we
only need to install mongodb once in the container but won't use the
repository afterwards. This avoids checking the mongodb repository in
"apt update".

Change-Id: I5a0455a4dbf8a31366bff65fd011fd5494b64ea7

testenv: podman: don't install GUI packages

Install erlang-nox and use the pre-built rebar3 as linked from
rebar3.org, instead of using the Debian package to avoid pulling in
~600 MB of GUI dependencies.

Related: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1083096
Change-Id: I27f58d1f102cf85ff7ff301c52696b65150e2898

ggsn: osmo-ggsn.src.cfg: tweak log output

* Print log levels.
* Don't print categories as hex.
* Print the basename at the end of the line.
* Remove "logging level lgtp debug", there already is
  "logging level lgtp info" further above, and this is a more sensible
  setting. With "debug" there are way too many log messages in e.g.
  TC_lots_of_concurrent_pdp_ctx.

Change-Id: I771d07645ea6da91f2c93f0954d99a37c866629a

ggsn: testenv: replace dummy netdev with bridge

Replace the dummy netdev that was used as network device reachable
through the GTP tunnel that can answer ICMP, with a bridge device. The
bridge device fulfils the same purpose, plus it can be used in a future
patch to connect osmo-ggsn when it is running in QEMU with the
testsuite.

Change-Id: I102d5b9ed0b3cafc263ad489ed4d4652f5e6dac8