Unauthorized route migration for routes owned by obs-ai-assistant,security-solution (elastic#198338)

### Authz API migration for unauthorized routes

This PR migrates unauthorized routes owned by your team to a new
security configuration.
Please refer to the documentation for more information: [Authorization
API](https://docs.elastic.dev/kibana-dev-docs/key-concepts/security-api-authorization)

### **Before migration:**
```ts
router.get({
  path: '/api/path',
  ...
}, handler);
```

### **After migration:**
```ts
router.get({
  path: '/api/path',
  security: {
    authz: {
      enabled: false,
      reason: 'This route is opted out from authorization because ...',
    },
  },
  ...
}, handler);
```

### What to do next?
1. Review the changes in this PR.
2. Elaborate on the reasoning to opt-out of authorization.
3. Routes without a compelling reason to opt-out of authorization should
plan to introduce them as soon as possible.
2. You might need to update your tests to reflect the new security
configuration:
  - If you have snapshot tests that include the route definition.

## Any questions?
If you have any questions or need help with API authorization, please
reach out to the `@elastic/kibana-security` team.

Co-authored-by: Ashokaditya <[email protected]>
Co-authored-by: Viduni Wickramarachchi <[email protected]>

Author: 3 people

x-pack/platform/plugins/private/data_usage/server/routes/internal/data_streams.ts

@@ -22,6 +22,12 @@ export const registerDataStreamsRoute = (
     .addVersion(
       {
         version: '1',
+        security: {
+          authz: {
+            enabled: false,
+            reason: 'This route is opted out from authorization',
+          },
+        },
         validate: {
           request: DataStreamsRequestSchema,
           response: {

x-pack/platform/plugins/private/data_usage/server/routes/internal/usage_metrics.ts

@@ -23,6 +23,12 @@ export const registerUsageMetricsRoute = (
     .addVersion(
       {
         version: '1',
+        security: {
+          authz: {
+            enabled: false,
+            reason: 'This route is opted out from authorization',
+          },
+        },
         validate: {
           request: {
             body: UsageMetricsRequestSchema,