Fix flaky CreateIndex method (#3698)

Use unique ES index names in tests

Author: MichaelSnowden

host/testdata/integration_elasticsearch_cluster.yaml

@@ -12,4 +12,4 @@ esconfig:
     scheme: "http"
     host: "${ES_SEEDS}:9200"
   indices:
-    visibility: test-visibility-
+    visibility: test-visibility-ad8388-

host/testdata/integration_namespace_cluster.yaml

@@ -13,4 +13,4 @@ esconfig:
     scheme: "http"
     host: "${ES_SEEDS}:9200"
   indices:
-    visibility: test-visibility-
+    visibility: test-visibility-28e9c5-

host/testdata/schedule_integration_test_cluster_adv_vis.yaml

@@ -11,4 +11,4 @@ esconfig:
     scheme: "http"
     host: "${ES_SEEDS}:9200"
   indices:
-    visibility: test-visibility-
+    visibility: test-visibility-3c863e-

host/testdata/xdc_integration_es_clusters.yaml

@@ -25,7 +25,7 @@
       scheme: "http"
       host: "${ES_SEEDS}:9200"
     indices:
-      visibility: test-visibility-0-
+      visibility: test-visibility-4b3e75-
 
 - persistence:
     dbname: integration_standby_es
@@ -54,4 +54,4 @@
       scheme: "http"
       host: "${ES_SEEDS}:9200"
     indices:
-      visibility: test-visibility-1-
+      visibility: test-visibility-73af9f-