rgw multisite: check connection for realm endpoint
rgw multisite: check connection for realm endpoint

This commit adds connection checks before realm pulls
Curls are performed on the endpoint being pulled from
the mons and the rgws

Closes: https://bugzilla.redhat.com/show_bug.cgi?id=1731158

Signed-off-by: Ali Maredia <fe8379b4313c3a8f13a448418c8783dd04b778fa@redhat.com>

ceph/ceph-ansible,ceph/ceph-ansible