* Update the tests to start using tests.systemd tool instead of systemd.sh helper
This is the second part of the migration from systemd.sh helper to
tests.systemd tool
* fix names of stop-unit command
* fix op-remove-retry test
* tests: skip proxy test if https{,s}_proxy is set
The tinyproxy in the proxy test uses socket.socket(AF_INET) to connect
o the target for https and on systems that do not allow direct
connections to the outside world 443 port this will fail.
* tests: skip network-retry if http{,s}_proxy is set
The network-retry test may fail when http_proxy is set because
it breaks DNS for the test. However if the proxy is available
and defined via an IP instead of a DNS name the test will not
work because the DNS is bypassed.
* tests: skip snap-service-watchdog in autopkgtest
Skip autopkgtest as this test is timing dependent and ADT is often
very slow.
Also fixes a incorrect print in the watchdog service binary:
lib/snaps/test-snapd-service-watchdog/bin/direct
which lead to misleading:
```
Jan 09 20:28:55 autopkgtest test-snapd-service-watchdog.direct-watchdog-ok[21555]: INFO:root:watchdog notification every 0s
output
```
* address review feedback (thanks to John)
* test: review feedback for network-retry (thanks to mborzecki)
* tests: do not run some tests in autopkgtest
We get timeouts in autopkgtest on amd64 currently so this disables
some of the slower running tests in this environment. The real
issue is that the cloud that runs the autopkgtest is slow dues to
overcommitment it seems. But this is a reasonable workaround for
now.
* tests: re-enable install-store in ADT, disable snapctl-services/nfs-support
The tinyproxy has a bit of a startup delay (python init and all that).
This means that sometimes in tests the proxy is not fully ready when
the test tries to talk to it. This PR makes the proxy a "notify"
service that only notifies after the proxy is ready.
We got a bugreport (LP: 1791587) that the proxy.http setting is
not honored in snapd on classic systems when no core is installed.
This PR adds a test to ensure this works.
