Elasticsearch: Add support for date_nanos type (#27538)

public/app/plugins/datasource/elasticsearch/datasource.test.ts

@@ -384,6 +384,7 @@ describe('ElasticDatasource', function(this: any) {
                   properties: {
                     '@timestamp': { type: 'date' },
                     __timestamp: { type: 'date' },
+                    '@timestampnano': { type: 'date_nanos' },
                     beat: {
                       properties: {
                         name: {
@@ -431,6 +432,7 @@ describe('ElasticDatasource', function(this: any) {
       expect(fields).toEqual([
         '@timestamp',
         '__timestamp',
+        '@timestampnano',
         'beat.name.raw',
         'beat.name',
         'beat.hostname',
@@ -460,7 +462,7 @@ describe('ElasticDatasource', function(this: any) {
       });
 
       const fields = _.map(fieldObjects, 'text');
-      expect(fields).toEqual(['@timestamp', '__timestamp']);
+      expect(fields).toEqual(['@timestamp', '__timestamp', '@timestampnano']);
     });
   });
 

public/app/plugins/datasource/elasticsearch/datasource.ts

@@ -453,6 +453,7 @@ export class ElasticDatasource extends DataSourceApi<ElasticsearchQuery, Elastic
         integer: 'number',
         long: 'number',
         date: 'date',
+        date_nanos: 'date',
         string: 'string',
         text: 'string',
         scaled_float: 'number',