QA: Preserve templates and snapshot on upgrades

Monitoring wasn't consistently creating its templates when the rolling
upgrade test case was running against the zip distribution. It looked
like the templates were being removed as soon as they were created:
```
[2018-05-29T15:33:38,311][DEBUG][o.e.c.s.ClusterApplierService] [node-0] processing [apply cluster state (from master [master {node-0}{9cTSjfGtQyeoSNxIRF_BdQ}{SI9wsZjeQUKAAhBavEnOPQ}{127.0.0.1}{127.0.0.1:45985}{ml.machine_memory=33651564544, xpack.installed=true, testattr=test, ml.max_open_jobs=20, ml.enabled=true} committed version [160] source [create-index-template [.monitoring-kibana], cause [api]]])]: took [11ms] done applying updated cluster state (version: 160, uuid: z0cPB7DkQceXohOOzYgRRg)
[2018-05-29T15:33:40,752][INFO ][o.e.c.m.MetaDataIndexTemplateService] [node-0] removing template [.monitoring-es]
[2018-05-29T15:33:40,752][INFO ][o.e.c.m.MetaDataIndexTemplateService] [node-0] removing template [.monitoring-alerts]
[2018-05-29T15:33:40,752][INFO ][o.e.c.m.MetaDataIndexTemplateService] [node-0] removing template [.monitoring-kibana]
[2018-05-29T15:33:40,752][INFO ][o.e.c.m.MetaDataIndexTemplateService] [node-0] removing template [.monitoring-logstash]
[2018-05-29T15:33:40,752][INFO ][o.e.c.m.MetaDataIndexTemplateService] [node-0] removing template [.monitoring-beats]
```

It turns out that this was my fault. I had configured the tests to
delete the templates. This change configures the tests to keep the
templates and any snapshots we make for good measure. This causes the
`.monitoring-*` templates to be in the cluster state when we look for
them.

Closes #30925

Author: nik9000

qa/rolling-upgrade/src/test/java/org/elasticsearch/upgrades/AbstractRollingTestCase.java

@@ -53,6 +53,16 @@ protected final boolean preserveReposUponCompletion() {
         return true;
     }
 
+    @Override
+    protected boolean preserveTemplatesUponCompletion() {
+        return true;
+    }
+
+    @Override
+    protected boolean preserveSnapshotsUponCompletion() {
+        return true;
+    }
+
     @Override
     protected final Settings restClientSettings() {
         return Settings.builder().put(super.restClientSettings())

qa/rolling-upgrade/src/test/java/org/elasticsearch/upgrades/UpgradeClusterClientYamlTestSuiteIT.java

@@ -31,12 +31,22 @@
 public class UpgradeClusterClientYamlTestSuiteIT extends ESClientYamlSuiteTestCase {
 
     @Override
-    protected boolean preserveIndicesUponCompletion() {
+    protected final boolean preserveIndicesUponCompletion() {
         return true;
     }
 
     @Override
-    protected boolean preserveReposUponCompletion() {
+    protected final boolean preserveReposUponCompletion() {
+        return true;
+    }
+
+    @Override
+    protected boolean preserveTemplatesUponCompletion() {
+        return true;
+    }
+
+    @Override
+    protected boolean preserveSnapshotsUponCompletion() {
         return true;
     }
 

qa/rolling-upgrade/src/test/java/org/elasticsearch/upgrades/XPackIT.java

@@ -87,6 +87,11 @@ public void testIndexTemplatesCreated() throws Exception {
             expectedTemplates.add(".ml-meta");
             expectedTemplates.add(".ml-notifications");
             expectedTemplates.add(".ml-state");
+            expectedTemplates.add(".monitoring-alerts");
+            expectedTemplates.add(".monitoring-beats");
+            expectedTemplates.add(".monitoring-es");
+            expectedTemplates.add(".monitoring-kibana");
+            expectedTemplates.add(".monitoring-logstash");
             expectedTemplates.add("logstash-index-template");
             expectedTemplates.add("security-index-template");
             expectedTemplates.add("security_audit_log");