Also track "insertions failed by dup key" metric when dup is in MRS
Also track "insertions failed by dup key" metric when dup is in MRS

Change-Id: Ie4dec3bb3dc343c03595122f1984f2a1ca333222
Reviewed-on: http://gerrit.ent.cloudera.com:8080/1459
Reviewed-by: Todd Lipcon <2c763d726a8c2f6afda9be7e0e56a2caa6bb5e6b@cloudera.com>
Tested-by: jenkins

cloudera/kudu,cloudera/kudu,helifu/kudu,InspurUSA/kudu,InspurUSA/kudu,helifu/kudu,cloudera/kudu,InspurUSA/kudu,helifu/kudu,EvilMcJerkface/kudu,EvilMcJerkface/kudu,EvilMcJerkface/kudu,andrwng/kudu,EvilMcJerkface/kudu,cloudera/kudu,cloudera/kudu,InspurUSA/kudu,helifu/kudu,andrwng/kudu,EvilMcJerkface/kudu,helifu/kudu,helifu/kudu,EvilMcJerkface/kudu,andrwng/kudu,andrwng/kudu,helifu/kudu,andrwng/kudu,cloudera/kudu,EvilMcJerkface/kudu,andrwng/kudu,InspurUSA/kudu,andrwng/kudu,andrwng/kudu,cloudera/kudu,cloudera/kudu,EvilMcJerkface/kudu,cloudera/kudu,helifu/kudu,EvilMcJerkface/kudu,helifu/kudu,InspurUSA/kudu,InspurUSA/kudu,InspurUSA/kudu,InspurUSA/kudu,andrwng/kudu