Fix testLeaderAndFollowerEntityOwnersReassignedAfterShutdown failure

14:19:15 Failed tests:
14:19:15   DistributedEntityOwnershipIntegrationTest.testLeaderAndFollowerEntityOwnersReassignedAfterShutdown:439->lambda$testLeaderAndFollowerEntityOwnersReassignedAfterShutdown$1:440 Raft state expected:<[Leader]> but was:<[Candidate]>

After the leader is shut down, member-2 is supposed to be elected leader but,
in this case, it didn't get the vote from member-5 b/c member-2 had not yet
received the MemberUp for member-5 and thus did not have its peer actor address.
So I made changes to ensure member data stores are ready and members are up.

I also saw a failure where member-3 or member5 didn't grant the vote for member-2
b/c it's last log index was greater. This can happen is member-2 didn't was a bit
behind when the leader was shut down. So I changes it to obtain the leader's last
index and verify the remaining follower's last log index is up-to-date.

Change-Id: Ib5ad2e135bb3809e1c62a432a029a5a56109190d
Signed-off-by: Tom Pantelis <tompantelis@gmail.com>