Code review comment for ~freyes/charm-grafana:bug/1872682

Functest failed with:

2021-04-13 10:53:55 [ERROR] {'model_apt_install': 'zaza-2010f9813ac7'}
2021-04-13 10:53:55 [ERROR] Model model_apt_install (zaza-2010f9813ac7)
Traceback (most recent call last):
  File "/home/xav/charms/charm-grafana/src/.tox/func/bin/functest-run-suite", line 8, in <module>
    sys.exit(main())
  File "/home/xav/charms/charm-grafana/src/.tox/func/lib/python3.8/site-packages/zaza/charm_lifecycle/func_test_runner.py", line 308, in main
    func_test_runner(
  File "/home/xav/charms/charm-grafana/src/.tox/func/lib/python3.8/site-packages/zaza/charm_lifecycle/func_test_runner.py", line 242, in func_test_runner
    run_env_deployment(env_deployment, keep_model=preserve_model,
  File "/home/xav/charms/charm-grafana/src/.tox/func/lib/python3.8/site-packages/zaza/charm_lifecycle/func_test_runner.py", line 122, in run_env_deployment
    deploy.deploy(
  File "/home/xav/charms/charm-grafana/src/.tox/func/lib/python3.8/site-packages/zaza/charm_lifecycle/deploy.py", line 385, in deploy
    zaza.model.wait_for_application_states(
  File "/home/xav/charms/charm-grafana/src/.tox/func/lib/python3.8/site-packages/zaza/__init__.py", line 77, in _wrapper
    return run(_run_it())
  File "/home/xav/charms/charm-grafana/src/.tox/func/lib/python3.8/site-packages/zaza/__init__.py", line 62, in run
    return task.result()
  File "/home/xav/charms/charm-grafana/src/.tox/func/lib/python3.8/site-packages/zaza/__init__.py", line 76, in _run_it
    return await f(*args, **kwargs)
  File "/home/xav/charms/charm-grafana/src/.tox/func/lib/python3.8/site-packages/zaza/model.py", line 1167, in async_wait_for_application_states
    await model.block_until(
  File "/home/xav/charms/charm-grafana/src/.tox/func/lib/python3.8/site-packages/juju/model.py", line 727, in block_until
    await utils.block_until(done,
  File "/home/xav/charms/charm-grafana/src/.tox/func/lib/python3.8/site-packages/juju/utils.py", line 87, in block_until
    await asyncio.wait_for(_block(), timeout, loop=loop)
  File "/usr/lib/python3.8/asyncio/tasks.py", line 490, in wait_for
    raise exceptions.TimeoutError()
asyncio.exceptions.TimeoutError

Bundle it was deploying: src/tests/functional/tests/bundles/focal-tls.yaml