_lastUpdated search param not recognized as a valid sort specification when Full-text indexing is enabled

[AbayomiE-T]

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https://github.com/hapifhir/hapi-fhir/wiki/Getting-Help

Describe the bug
A clear and concise description of what the bug is.

To Reproduce
Steps to reproduce the behavior:

1. Go to Smile Web Admin Console
2. In the Persistence module, got to the 'Full-Text indexing' section set Full-Text Indexing Enabled to yes.
3. In the same section, set Enable Indexing of Search Parameters (experimental) and Store resource bodies in the Full-Text index (experimental) to yes.
4. Send a POST request to http://localhost:8000/CodeSystem/$apply-codesystem-delta-add and add this to the payload:

{
    "parameter": [
        {
            "name": "system",
            "valueUri": "http://example.com/cs"
        },
        {
            "resource": {
                "concept": [
                    {
                        "code": "CHEM",
                        "display": "Chemistry",
                        "concept": [
                            {
                                "code": "HB",
                                "display": "Hemoglobin"
                            },
                            {
                                "code": "NEUT",
                                "display": "Neutrophils"
                            }
                        ]
                    },
                    {
                        "code": "MICRO",
                        "display": "Microbiology",
                        "concept": [
                            {
                                "code": "C&S",
                                "display": "Culture And Sensitivity"
                            }
                        ]
                    }
                ],
                "resourceType": "CodeSystem"
            },
            "name": "codeSystem"
        }
    ],
    "resourceType": "Parameters"
}

Expected behavior
Should return a 200 OK response with the object looking similar to:

{
    "resourceType": "Parameters",
    "parameter": [
        {
            "name": "conceptCount",
            "valueInteger": 5
        },
        {
            "name": "target",
            "valueReference": {
                "reference": "CodeSystem/1352"
            }
        }
    ]
}

Observed Results
response 500, HAPI-0389: Failed to call access method: org.springframework.dao.InvalidDataAccessApiUsageException: HAPI-2523: Invalid sort specification: _lastUpdated