Add integ test for queue rejection cluster RCA

[rguo-aws]

Issue #:

Description of changes:
This PR will add integ test for queue rejection cluster RCA. Will add integ tests for decision maker & auto tuning piece in a separate PR.

Tests:
n/a

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.

[codecov]

Codecov Report

Merging #370 into master will increase coverage by 1.89%.
The diff coverage is n/a.

@@             Coverage Diff              @@
##             master     #370      +/-   ##
============================================
+ Coverage     67.78%   69.67%   +1.89%     
- Complexity     2133     2235     +102     
============================================
  Files           301      301              
  Lines         13402    13402              
  Branches       1110     1110              
============================================
+ Hits           9084     9338     +254     
+ Misses         3922     3703     -219     
+ Partials        396      361      -35     

Impacted Files	Coverage Δ	Complexity Δ
...formanceanalyzer/rca/net/tasks/FlowUnitTxTask.java	86.84% <0.00%> (-10.53%)	6.00% <0.00%> (ø%)
...asticsearch/performanceanalyzer/net/NetServer.java	79.74% <0.00%> (-2.54%)	21.00% <0.00%> (-1.00%)
...manceanalyzer/rca/persistence/SQLitePersistor.java	68.51% <0.00%> (+0.42%)	28.00% <0.00%> (+1.00%)
...ca/framework/api/summaries/HotResourceSummary.java	88.12% <0.00%> (+0.62%)	23.00% <0.00%> (+2.00%)
...performanceanalyzer/collectors/StatsCollector.java	91.26% <0.00%> (+0.79%)	36.00% <0.00%> (+1.00%)
...analyzer/rca/store/rca/cluster/BaseClusterRca.java	93.02% <0.00%> (+2.32%)	29.00% <0.00%> (+1.00%)
...erformanceanalyzer/rca/scheduler/RCAScheduler.java	70.23% <0.00%> (+2.38%)	12.00% <0.00%> (ø%)
...lyzer/rca/store/collector/NodeConfigCollector.java	79.31% <0.00%> (+3.44%)	12.00% <0.00%> (+1.00%)
...yzer/rca/store/rca/hotheap/NodeStatAggregator.java	95.34% <0.00%> (+4.65%)	13.00% <0.00%> (+1.00%)
...zer/rca/store/rca/hotshard/HotShardClusterRca.java	94.56% <0.00%> (+5.43%)	18.00% <0.00%> (+2.00%)
... and 29 more

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update e121192...ff24fbf. Read the comment docs.