[ResponseOps][Alerting] Index threshold alert can't use unsigned long data type (#138452)

* Adding unsigned_long

* Reverting comment change

Co-authored-by: Kibana Machine <42973632+kibanamachine@users.noreply.github.com>

x-pack/plugins/triggers_actions_ui/server/data/routes/fields.ts

@@ -138,4 +138,5 @@ const normalizedFieldTypes: Record<string, string> = {
   float: 'number',
   half_float: 'number',
   scaled_float: 'number',
+  unsigned_long: 'number',
 };

x-pack/test/alerting_api_integration/common/lib/es_test_index_tool.ts

@@ -50,6 +50,9 @@ export class ESTestIndexTool {
               testedValue: {
                 type: 'long',
               },
+              testedValueUnsigned: {
+                type: 'unsigned_long',
+              },
               group: {
                 type: 'keyword',
               },

x-pack/test/alerting_api_integration/spaces_only/tests/alerting/builtin_alert_types/index_threshold/alert.ts

@@ -265,6 +265,45 @@ export default function ruleTests({ getService }: FtrProviderContext) {
       expect(inGroup2).to.be.greaterThan(0);
     });
 
+    it('runs correctly: max grouped on unsigned long', async () => {
+      await createRule({
+        name: 'never fire',
+        aggType: 'max',
+        aggField: 'testedValueUnsigned',
+        groupBy: 'top',
+        termField: 'group',
+        termSize: 2,
+        thresholdComparator: '<',
+        threshold: [Number.MAX_SAFE_INTEGER],
+      });
+
+      await createRule({
+        name: 'always fire',
+        aggType: 'max',
+        aggField: 'testedValueUnsigned',
+        groupBy: 'top',
+        termField: 'group',
+        termSize: 2, // two actions will fire each interval
+        thresholdComparator: '>=',
+        threshold: [Number.MAX_SAFE_INTEGER],
+      });
+
+      // create some more documents in the first group
+      await createEsDocumentsInGroups(1);
+
+      const docs = await waitForDocs(4);
+
+      for (const doc of docs) {
+        const { name, message } = doc._source.params;
+
+        expect(name).to.be('always fire');
+
+        const messagePattern =
+          /alert 'always fire' is active for group \'group-\d\':\n\n- Value: \d+\n- Conditions Met: max\(testedValueUnsigned\) is greater than or equal to \d+ over 15s\n- Timestamp: \d{4}-\d{2}-\d{2}T\d{2}:\d{2}:\d{2}.\d{3}Z/;
+        expect(message).to.match(messagePattern);
+      }
+    });
+
     it('runs correctly: min grouped', async () => {
       await createRule({
         name: 'never fire',

x-pack/test/alerting_api_integration/spaces_only/tests/alerting/builtin_alert_types/index_threshold/create_test_data.ts

@@ -65,6 +65,7 @@ async function createEsDocument(
     date: new Date(epochMillis).toISOString(),
     date_epoch_millis: epochMillis,
     testedValue,
+    testedValueUnsigned: '18446744073709551615',
     group,
     '@timestamp': new Date(epochMillis).toISOString(),
   };