mgr/cephadm: set dashboard grafana-api-password when user provides one

mgr/cephadm: set dashboard grafana-api-password when user provides one

If a user provides this in the spec, cephadm will set up the inital admin
user with the given password, but the conig setting accessed with
"ceph dashboard get-grafana-api-password" is never updated. Cephadm
can handle updating it since it's the one setting the password.

Fixes: https://tracker.ceph.com/issues/57095
Signed-off-by: Adam King <adking@redhat.com>
(cherry picked from commit c7d84f93b11915b2668af225eedd33781bb9a07b)

Conflicts:
	src/pybind/mgr/cephadm/services/ingress.py