V2: Provide fleet configuration to APM server

[aleksmaus]

What does this PR do?

Injects the fleet configuration for APM the same way it was done for Endpoint.
Tested against APM PR for V2 elastic/apm-server#9544

Why is it important?

Fixes Agent with APM for V2.

Checklist

• My code follows the style guidelines of this project
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• I have made corresponding change to the default configuration files
• I have added tests that prove my fix is effective or that my feature works
• I have added an entry in CHANGELOG.next.asciidoc or CHANGELOG-developer.next.asciidoc.

Related issues

• Closes V2: Provide fleet configuration to APM server #1737

Logs

The following is the APM input configuration captured in apm-server built off of the PR elastic/apm-server#9544

{
    "apm-server": {
        "agent_config": [],
        "aggregation": {
            "service": {
                "enabled": false
            }
        },
        "auth": {
            "anonymous": {
                "allow_agent": [
                    "rum-js",
                    "js-base",
                    "iOS/swift"
                ],
                "allow_service": null,
                "enabled": true,
                "rate_limit": {
                    "event_limit": 300,
                    "ip_limit": 1000
                }
            },
            "api_key": {
                "enabled": false,
                "limit": 100
            },
            "secret_token": null
        },
        "capture_personal_data": true,
        "default_service_environment": null,
        "expvar": {
            "enabled": false
        },
        "host": "localhost:8255",
        "idle_timeout": "45s",
        "java_attacher": {
            "discovery-rules": null,
            "download-agent-version": null,
            "enabled": false
        },
        "max_connections": 0,
        "max_event_size": 307200,
        "max_header_size": 1048576,
        "pprof": {
            "enabled": false
        },
        "read_timeout": "3600s",
        "response_headers": null,
        "rum": {
            "allow_headers": null,
            "allow_origins": [
                "*"
            ],
            "enabled": true,
            "exclude_from_grouping": "^/webpack",
            "library_pattern": "node_modules|bower_components|~",
            "response_headers": null,
            "source_mapping": {
                "metadata": []
            }
        },
        "sampling": {
            "tail": {
                "enabled": false,
                "interval": "1m",
                "policies": [
                    {
                        "sample_rate": 0.1
                    }
                ],
                "storage_limit": "3GB"
            }
        },
        "shutdown_timeout": "30s",
        "ssl": {
            "certificate": null,
            "cipher_suites": null,
            "curve_types": null,
            "enabled": false,
            "key": null,
            "key_passphrase": null,
            "supported_protocols": [
                "TLSv1.1",
                "TLSv1.2",
                "TLSv1.3"
            ]
        },
        "write_timeout": "30s"
    },
    "data_stream": {
        "namespace": "default"
    },
    "fleet": {
        "access_api_key": "xxxxxxdvUUJITm80OFQyb1YwOU86clBNalZ2ZjNUM0M5a0U2SEgzc2N4Zw==",
        "agent": {
            "id": "ea466602-1c24-4704-8054-28fbacbf3e96"
        },
        "enabled": true,
        "host": {
            "id": "2628AB39-F770-5FC3-B7F1-8CC95E506B0D"
        },
        "hosts": [
            "https://ffffe9b5f47d409099163e5e8e5e4f4e.fleet.us-west2.gcp.elastic-cloud.com:443"
        ],
        "protocol": "http",
        "ssl": {
            "renegotiation": "never",
            "verification_mode": "full"
        },
        "timeout": "10m0s"
    },
    "id": "a055c8da-5886-4989-b969-8b6674666711",
    "meta": {
        "package": {
            "name": "apm",
            "version": "8.6.0"
        }
    },
    "name": "apm-1",
    "package_policy_id": "a055c8da-5886-4989-b969-8b6674666711",
    "policy": {
        "revision": 3
    },
    "revision": 2,
    "type": "apm"
}

[cmacknz]

Thanks for doing this so quickly!

[cmacknz]

@axw FYI

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• Start Time: 2022-11-17T00:48:37.898+0000

• Duration: 18 min 15 sec

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Total	4494

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