Fixes serviceStatus json output

[dlmarion]

This change removes the StatusSummary.serviceType
field from the json serialization. The serviceType field is redundant in the json output as the same
information is used as the key in a map that contains the StatusSummary object.

This change also removes the StatusSummary.serviceByGroups field from the json serialization using a custom
ExclusionStrategy.

Closes #6088

[dlmarion]

The output before this change is shown at #6088 (comment)

The output after this change is below:

./accumulo admin serviceStatus --json
...
        "T_SERVER": {
            "resourceGroups": {
                "default": 1
            },
            "serviceCount": 1,
            "errorCount": 0
        }
...

./accumulo admin serviceStatus --json --showHosts
...
        "T_SERVER": {
            "resourceGroups": {
                "default": 1
            },
            "serviceByGroups": {
                "default": [
                    "localhost:9997"
                ]
            },
            "serviceCount": 1,
            "errorCount": 0
        }
...