Instead of blindly waiting long enough for a disruptive change to
have been observed by the old leader and followers, we instead rely
on the approximation that checkOnlyLeaderCanWrite provides - i.e.
only a single actor believes they are the leader. This does not
account for clients that were in the followers list before and after
the disruptive change, but it serves as a reasonable approximation.
Signed-off-by: Monis Khan <mok@vmware.com>