Isolate users of JsonLogRecordServerUtil from the json library used.

JsonLogRecordServerUtil used to throw and org.jsonJSONException when
an error occurred parsing JSON or when expected JSON properties were
not found; now the exception thrown by the JSON library is encapsulated
in an InvalidJsonLogRecordFormatException.

Change-Id: I9d3643a5d2d6e29525ef5183006ac35fbe7a2af4