Merge pull request #48100 from adk3798/wip-57427-pacific

pacific: mgr/cephadm: allow setting prometheus retention time

Reviewed-by: Anthony D'Atri <anthonyeleven@users.noreply.github.com>

diff --cc src/cephadm/cephadm
Simple merge

diff --cc src/pybind/mgr/cephadm/services/monitoring.py
Simple merge

diff --cc src/pybind/mgr/cephadm/tests/test_services.py
Simple merge