Remove output_id from apm package policy (#142331) (#142371)

(cherry picked from commit 62734e6236)

Co-authored-by: Giorgos Bamparopoulos <georgios.bamparopoulos@elastic.co>

x-pack/plugins/apm/public/components/fleet_integration/apm_agents/runtime_attachment/runtime_attachment.stories.tsx

@@ -118,7 +118,6 @@ const policy = {
   namespace: 'default',
   policy_id: 'policy-elastic-agent-on-cloud',
   enabled: true,
-  output_id: '',
   inputs: [
     {
       type: 'apm',
@@ -341,7 +340,6 @@ const newPolicy = {
   namespace: 'default',
   policy_id: 'policy-elastic-agent-on-cloud',
   enabled: true,
-  output_id: '',
   package: {
     name: 'apm',
     title: 'Elastic APM',

x-pack/plugins/apm/public/components/fleet_integration/apm_policy_form/edit_apm_policy_form.stories.tsx

@@ -81,7 +81,6 @@ const policy = {
   namespace: 'default',
   enabled: true,
   policy_id: 'policy-elastic-agent-on-cloud',
-  output_id: '',
   package: {
     name: 'apm',
     version: '8.3.0',

x-pack/plugins/apm/server/routes/fleet/get_apm_package_policy_definition.ts

@@ -40,7 +40,6 @@ export async function getApmPackagePolicyDefinition({
     namespace: 'default',
     enabled: true,
     policy_id: POLICY_ELASTIC_AGENT_ON_CLOUD,
-    output_id: '',
     inputs: [
       {
         type: 'apm',

x-pack/plugins/apm/server/routes/fleet/source_maps.test.ts

@@ -19,7 +19,6 @@ const packagePolicy = {
   namespace: 'default',
   policy_id: '7a87c160-c961-11eb-81e2-f7327d61c92a',
   enabled: true,
-  output_id: '',
   inputs: [
     {
       policy_template: 'apmserver',