mgr/localpool: fix rule selection

mgr/localpool: fix rule selection

The 'osd pool create' arg parsing is broken; the rule name for
'ceph osd pool create $name $numpgs replicated $rulename' is passed
via the erasure_code_profile param.  Too many req=false options
without a way to disambiguate them.

Work around it by passing both 'rule' and 'erasure_code_profile'
keys, so that if/when the hack in OSDMonitor.cc is removed it will
still work.  Blech.

Signed-off-by: Sage Weil <sage@redhat.com>