Fix intermittent testFlipMemberVotingStates failure

Failure was see in auto-release:

ClusterAdminRpcServiceTest.testFlipMemberVotingStates:976->lambda$testFlipMemberVotingStates$8:978 Expected leader member-1. Actual: member-1-shard-cars-oper_testFlipMemberVotingStates

The test output showed it timed out trying to transfer leadership to member-3. The
timeout deadline is the election timeout interval which is the
heartbeatInterval * election-timeout-factor which were set to 300 and 1.
It seems 300ms is a bit too low for comfort so I changed it to 1000ms (100 * 10);

Change-Id: I1e3c79de960dcced8af71fecdf1ab8bdba433448
Signed-off-by: Tom Pantelis <tompantelis@gmail.com>