QueueBasedRouting: Use Running Count as fallback logic

[akhurana001]

Changes:

• Use running count as a fallback if queue count are the same. This doesn't change the core algo, just passes in running-counts if queuecounts are the same for a routing group.
• Some other minor changes/clean-up/version fixes to resolve some build errors.

[akhurana001]

shall we udpate getEligibleBackEnd function to make use of the new function? Also, can we apply the same strategy for the fall back function provideAdhocBackend, if there is no routing group provided

@charlessong-lyft The change here would generate the weights using running-counts if the queueLen is the same and getEligibleBackEnd already uses those weights to route so there shouldn't be any other change required : https://github.com/lyft/presto-gateway/blob/master/gateway-ha/src/main/java/com/lyft/data/gateway/ha/router/PrestoQueueLengthRoutingTable.java#L261 .

Same for provideAdhocBackend which already uses getEligibleBackEnd.

[charlessong-lyft]

chatted offline, LGTM now!