mgr/cephadm: add test coverage for action chosen in _check_daemons

mgr/cephadm: add test coverage for action chosen in _check_daemons

Add a test that verifies that the special cases for the ingress daemon
when fronting nfs choice of action is handled.

Fix the error in the current code block so that the test passes. I have
discussed this with Shweta, the author of this code block, and we
agree it should have been `last_deps`.

NOTE: While this test tries to assert the correct action is chosen via a
mock, I have also examined that it takes the correct code path when by
viewing coverage results locally.

Co-authored-by: Shweta Bhosale <Shweta.Bhosale1@ibm.com>
Signed-off-by: John Mulligan <jmulligan@redhat.com>