Only report `bug warning` in precise conditions. (#7772)

* Only report `bug warning` in precise conditions.

* Add a test check for template existing.

oap-server/server-library/library-elasticsearch-client/src/test/java/org/apache/skywalking/library/elasticsearch/ITElasticSearchTest.java

@@ -99,6 +99,8 @@ public class ITElasticSearchTest {
         assertThat(templateClient.createOrUpdate(name, ImmutableMap.of(), mappings, 0))
             .isTrue();
 
+        assertThat(templateClient.exists(name)).isTrue();
+
         assertThat(templateClient.get(name))
             .isPresent()
             .map(IndexTemplate::getMappings)

oap-server/server-storage-plugin/storage-elasticsearch-plugin/src/main/java/org/apache/skywalking/oap/server/storage/plugin/elasticsearch/base/StorageEsInstaller.java

@@ -70,14 +70,17 @@ public class StorageEsInstaller extends ModelInstaller {
         if (!model.isTimeSeries()) {
             return esClient.isExistsIndex(tableName);
         }
-        boolean exist = esClient.isExistsTemplate(tableName)
-            && esClient.isExistsIndex(TimeSeriesUtils.latestWriteIndexName(model));
+        boolean templateExists = esClient.isExistsTemplate(tableName);
         final Optional<IndexTemplate> template = esClient.getTemplate(tableName);
+        boolean lastIndexExists = esClient.isExistsIndex(TimeSeriesUtils.latestWriteIndexName(model));
 
-        if ((exist && !template.isPresent()) || (!exist && template.isPresent())) {
-            throw new Error("[Bug warning]ElasticSearch client query template result is not consistent. Please file an issue to Apache SkyWalking.(https://github.com/apache/skywalking/issues)");
+        if ((templateExists && !template.isPresent()) || (!templateExists && template.isPresent())) {
+            throw new Error("[Bug warning] ElasticSearch client query template result is not consistent. " +
+                                "Please file an issue to Apache SkyWalking.(https://github.com/apache/skywalking/issues)");
         }
 
+        boolean exist = templateExists && lastIndexExists;
+
         if (exist && IndexController.INSTANCE.isMetricModel(model)) {
             structures.putStructure(
                 tableName, template.get().getMappings()