[main][Automation] Update versions (#5820)

These files are used for picking the starting (pre-upgrade) or ending (post-upgrade) agent versions in upgrade integration tests.

The content is based on responses from https://www.elastic.co/api/product_versions and https://snapshots.elastic.co

The current update is generated based on the following requirements:

Package version: 9.0.0

```json
{
  "UpgradeToVersion": "9.0.0",
  "CurrentMajors": 1,
  "PreviousMajors": 1,
  "PreviousMinors": 2,
  "SnapshotBranches": [
    "8.15",
    "8.x",
    "7.17"
  ]
}
```

Co-authored-by: github-actions[bot] <41898282+github-actions[bot]@users.noreply.github.com>
Co-authored-by: Denis <[email protected]>

.package-version

@@ -1 +1 @@
-8.16.0
+9.0.0

pkg/testing/ess/create_deployment_request.tmpl.json

@@ -83,7 +83,9 @@
           "kibana": {
             "version": "{{ .request.Version }}",
             "user_settings_json": {
-              "xpack.fleet.enableExperimental": ["agentTamperProtectionEnabled"]
+              "xpack.fleet.enableExperimental": ["agentTamperProtectionEnabled"],
+              "xpack.fleet.internal.registry.kibanaVersionCheckEnabled": false,
+              "server.restrictInternalApis": false
             }
           }
         },
@@ -99,4 +101,4 @@
     "system_owned": false,
     "tags": {{ json .request.Tags }}
   }
-}
+}

testing/integration/testdata/.upgrade-test-agent-versions.yml

@@ -6,7 +6,7 @@
 
 testVersions:
   - 8.16.0-SNAPSHOT
-  - 8.15.2-SNAPSHOT
-  - 8.15.1
-  - 8.15.0
+  - 8.15.3
+  - 8.15.3-SNAPSHOT
+  - 8.15.2
   - 7.17.25-SNAPSHOT