[APM] Update Indices API to support sourcemap param (#177847)

closes #177820

Saved Object before: 

```
 "attributes": {
    "apmIndices": {
      "onboarding": "caue",
      "sourcemap": "foo-*"
    },
    "isSpaceAware": true
  },
```
<img width="1826" alt="Screenshot 2024-02-28 at 17 47 12"
src="https://github.com/elastic/kibana/assets/55978943/e44d90ec-982c-4330-88dc-14f0f59bfce7">

Saved Object after:
```
"attributes": {
    "apmIndices": {
      "onboarding": "caue"
    },
    "isSpaceAware": true
  },
```

The API now accepts the `sourcemap` param.

x-pack/plugins/observability_solution/apm/scripts/test/api.js

@@ -102,11 +102,11 @@ if (server) {
 const cmd = [
   'node',
   ...(inspect ? ['--inspect-brk'] : []),
-  `../../../../../scripts/${ftrScript}`,
+  `../../../../../../scripts/${ftrScript}`,
   ...(grep ? [`--grep "${grep}"`] : []),
   ...(updateSnapshots ? [`--updateSnapshots`] : []),
   ...(bail ? [`--bail`] : []),
-  `--config ../../../../test/apm_api_integration/${license}/config.ts`,
+  `--config ../../../../../test/apm_api_integration/${license}/config.ts`,
 ].join(' ');
 
 console.log(`Running: "${cmd}"`);

x-pack/plugins/observability_solution/apm/scripts/test/e2e.js

@@ -58,7 +58,7 @@ if (cypressCliArgs.grep) {
 }
 
 const spawnArgs = [
-  `../../../../scripts/${ftrScript}`,
+  `../../../../../scripts/${ftrScript}`,
   `--config=./ftr_config.ts`,
   `--kibana-install-dir=${argv.kibanaInstallDir}`,
   ...(argv.bail ? [`--bail`] : []),

x-pack/plugins/observability_solution/apm/server/routes/settings/apm_indices/route.ts

@@ -55,13 +55,21 @@ const saveApmIndicesRoute = createApmServerRoute({
       span: t.string,
       transaction: t.string,
       metric: t.string,
+      // Keeping this one here for backward compatibility
+      sourcemap: t.string,
     } as SaveApmIndicesBodySchema),
   }),
   handler: async (resources): Promise<SavedObject<{}>> => {
     const { params, context } = resources;
     const { body } = params;
     const savedObjectsClient = (await context.core).savedObjects.client;
-    return await saveApmIndices(savedObjectsClient, body);
+    const indices = { ...body };
+    if (indices.sourcemap) {
+      // Delete this as we stopped supporting it from 8.7.
+      delete indices.sourcemap;
+    }
+
+    return await saveApmIndices(savedObjectsClient, indices);
   },
 });
 

x-pack/test/apm_api_integration/tests/settings/apm_indices/apm_indices.spec.ts

@@ -6,6 +6,7 @@
  */
 
 import {
+  APMIndicesSavedObjectBody,
   APM_INDEX_SETTINGS_SAVED_OBJECT_ID,
   APM_INDEX_SETTINGS_SAVED_OBJECT_TYPE,
 } from '@kbn/apm-data-access-plugin/server/saved_objects/apm_indices';
@@ -71,5 +72,27 @@ export default function apmIndicesTests({ getService }: FtrProviderContext) {
       expect(readResponse.status).to.be(200);
       expect(readResponse.body.transaction).to.eql(INDEX_VALUE);
     });
+
+    it('updates apm indices removing legacy sourcemap', async () => {
+      const INDEX_VALUE = 'foo-*';
+
+      const writeResponse = await apmApiClient.writeUser({
+        endpoint: 'POST /internal/apm/settings/apm-indices/save',
+        params: {
+          body: { sourcemap: 'bar-*', transaction: INDEX_VALUE },
+        },
+      });
+      expect(writeResponse.status).to.be(200);
+      const savedAPMSavedObject = writeResponse.body
+        .attributes as Partial<APMIndicesSavedObjectBody>;
+      expect(savedAPMSavedObject.apmIndices?.transaction).to.eql(INDEX_VALUE);
+      expect(savedAPMSavedObject.apmIndices?.sourcemap).to.eql(undefined);
+
+      const readResponse = await apmApiClient.readUser({
+        endpoint: 'GET /internal/apm/settings/apm-indices',
+      });
+      expect(readResponse.body.transaction).to.eql(INDEX_VALUE);
+      expect(readResponse.body.sourcemap).to.eql('apm-*');
+    });
   });
 }