[obsUX][APM] Migrate APM metrics tests to agnostic deployment tests (e…

…lastic#200175)

### Summary
Closes elastic#198976
Part of elastic#193245

This PR contains the changes to migrate metrics test folder to
Deployment-agnostic testing strategy.

#### How to test
Serverless
```
node scripts/functional_tests_server --config x-pack/test/api_integration/deployment_agnostic/configs/serverless/oblt.serverless.config.ts
node scripts/functional_test_runner --config x-pack/test/api_integration/deployment_agnostic/configs/serverless/oblt.serverless.config.ts --grep="APM"
```
It's recommended to be run against
[MKI](https://github.com/crespocarlos/kibana/blob/main/x-pack/test_serverless/README.md#run-tests-on-mki)

Stateful
```
node scripts/functional_tests_server --config x-pack/test/api_integration/deployment_agnostic/configs/stateful/oblt.stateful.config.ts
node scripts/functional_test_runner --config x-pack/test/api_integration/deployment_agnostic/configs/stateful/oblt.stateful.config.ts --grep="APM"
```
Checks

- [ ] (OPTIONAL, only if a test has been unskipped) Run flaky test suite
- [x]  local run for serverless
- [x]  local run for stateful
- [x]  MKI run for serverless

x-pack/test/api_integration/deployment_agnostic/apis/observability/apm/index.ts

@@ -23,6 +23,7 @@ export default function apmApiIntegrationTests({
     loadTestFile(require.resolve('./correlations'));
     loadTestFile(require.resolve('./entities'));
     loadTestFile(require.resolve('./cold_start'));
+    loadTestFile(require.resolve('./metrics'));
     loadTestFile(require.resolve('./services'));
     loadTestFile(require.resolve('./historical_data'));
     loadTestFile(require.resolve('./observability_overview'));

x-pack/test/api_integration/deployment_agnostic/apis/observability/apm/metrics/index.ts

@@ -0,0 +1,19 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License
+ * 2.0; you may not use this file except in compliance with the Elastic License
+ * 2.0.
+ */
+
+import { DeploymentAgnosticFtrProviderContext } from '../../../../ftr_provider_context';
+
+export default function ({ loadTestFile }: DeploymentAgnosticFtrProviderContext) {
+  describe('metrics', () => {
+    loadTestFile(require.resolve('./metrics_charts.spec.ts'));
+    loadTestFile(require.resolve('./memory/memory_metrics.spec.ts'));
+    loadTestFile(require.resolve('./serverless/serverless_active_instances.spec.ts'));
+    loadTestFile(require.resolve('./serverless/serverless_functions_overview.spec.ts'));
+    loadTestFile(require.resolve('./serverless/serverless_metrics_charts.spec.ts'));
+    loadTestFile(require.resolve('./serverless/serverless_summary.spec.ts'));
+  });
+}

x-pack/test/apm_api_integration/tests/metrics/memory/memory_metrics.spec.ts → x-pack/test/api_integration/deployment_agnostic/apis/observability/apm/metrics/memory/memory_metrics.spec.ts

@@ -6,13 +6,13 @@
  */
 
 import expect from '@kbn/expect';
-import { FtrProviderContext } from '../../../common/ftr_provider_context';
+import type { ApmSynthtraceEsClient } from '@kbn/apm-synthtrace';
 import { config, generateData } from './generate_data';
+import { DeploymentAgnosticFtrProviderContext } from '../../../../../ftr_provider_context';
 
-export default function ApiTest({ getService }: FtrProviderContext) {
-  const registry = getService('registry');
-  const apmApiClient = getService('apmApiClient');
-  const apmSynthtraceEsClient = getService('apmSynthtraceEsClient');
+export default function ApiTest({ getService }: DeploymentAgnosticFtrProviderContext) {
+  const apmApiClient = getService('apmApi');
+  const synthtrace = getService('synthtrace');
 
   const start = new Date('2023-01-01T00:00:00.000Z').getTime();
   const end = new Date('2023-01-01T00:15:00.000Z').getTime() - 1;
@@ -33,9 +33,10 @@ export default function ApiTest({ getService }: FtrProviderContext) {
     });
   }
 
-  // FLAKY: https://github.com/elastic/kibana/issues/176990
-  registry.when('Memory', { config: 'trial', archives: [] }, () => {
+  describe('Memory', () => {
+    let apmSynthtraceEsClient: ApmSynthtraceEsClient;
     before(async () => {
+      apmSynthtraceEsClient = await synthtrace.createApmSynthtraceEsClient();
       await generateData({ start, end, apmSynthtraceEsClient });
     });