osd/PeeringState: do not start renewing leases until PG is activated

osd/PeeringState: do not start renewing leases until PG is activated

The activate() work renews the lease so that we can send lease info out
to the peers immediately.  However, these messages may get delayed.  Since
we immediately start scheduling renewals, it's possible for the renewal
to go out before the PG is active, crashing the replicas.

Fix by not scheduling renewals until the PG is really active.

Also, renew aggressively at that point in time, since it may have been a
while since we first started the activation.

Fixes: https://tracker.ceph.com/issues/44041
Signed-off-by: Sage Weil <sage@redhat.com>