[APM] Attempt to fix flaky test in service_group_count.spec.ts (elast…

…ic#204543)

## Summary

Fixes elastic#201267

Before migrating the API tests to be deployment-agnostic, we had already
seen some flaky results for this test
(elastic#197912). After completing the
migration, the error occurred again.

This PR aims to fix the potential issue by ensuring that all existing
alerts are cleared before creating the alerts used in the test case.

Co-authored-by: jennypavlova <[email protected]>

x-pack/test/api_integration/deployment_agnostic/apis/observability/apm/service_groups/service_group_count/service_group_count.spec.ts

@@ -27,6 +27,16 @@ export default function ApiTest({ getService }: DeploymentAgnosticFtrProviderCon
   const start = Date.now() - 24 * 60 * 60 * 1000;
   const end = Date.now();
 
+  const cleanUpAlerts = ({ roleAuthc, ruleId }: { roleAuthc: RoleCredentials; ruleId: string }) => {
+    return alertingApi.cleanUpAlerts({
+      roleAuthc,
+      ruleId,
+      alertIndexName: APM_ALERTS_INDEX,
+      connectorIndexName: APM_ACTION_VARIABLE_INDEX,
+      consumer: 'apm',
+    });
+  };
+
   describe('Service group counts', () => {
     let synthbeansServiceGroupId: string;
     let opbeansServiceGroupId: string;
@@ -73,6 +83,7 @@ export default function ApiTest({ getService }: DeploymentAgnosticFtrProviderCon
 
       before(async () => {
         roleAuthc = await samlAuth.createM2mApiKeyWithRoleScope('admin');
+        await cleanUpAlerts({ roleAuthc, ruleId });
         const createdRule = await alertingApi.createRule({
           name: 'Latency threshold | synth-go',
           params: {
@@ -94,13 +105,7 @@ export default function ApiTest({ getService }: DeploymentAgnosticFtrProviderCon
       });
 
       after(async () => {
-        await alertingApi.cleanUpAlerts({
-          roleAuthc,
-          ruleId,
-          alertIndexName: APM_ALERTS_INDEX,
-          connectorIndexName: APM_ACTION_VARIABLE_INDEX,
-          consumer: 'apm',
-        });
+        await cleanUpAlerts({ roleAuthc, ruleId });
         await samlAuth.invalidateM2mApiKeyWithRoleScope(roleAuthc);
       });