Refactor `AbstractSimpleTransportTestCase` and `MockTransportService` to not use `Version.transportVersion` 
test/framework/src/main/java/org/elasticsearch/transport/AbstractSimpleTransportTestCase.java
.put("network.tcp.keep_count", "14")
            .put("network.tcp.reuse_address", enable == false)
            .put("network.tcp.send_buffer_size", "4b")
            .put("network.tcp.receive_buffer_size", "3b")
            .put("network.publish_host", "another_publish_host")
            .put("network.bind_host", "another_bind_host")
            .build();
        Settings transportSettings = Settings.builder()
            .put("transport.tcp.no_delay", enable)
            .put("transport.tcp.keep_alive", enable)
            .put("transport.tcp.keep_idle", "42")
            .put("transport.tcp.keep_interval", "7")
            .put("transport.tcp.keep_count", "13")
            .put("transport.tcp.reuse_address", enable)
            .put("transport.tcp.send_buffer_size", "43000b")
            .put("transport.tcp.receive_buffer_size", "42000b")
            .put("transport.publish_host", "the_publish_host")
            .put("transport.port", "9700-9800")
            .put("transport.bind_host", "the_bind_host")
            .put(globalSettings2)
            .build();
        Settings transportSettings2 = Settings.builder()
            .put("transport.tcp.no_delay", enable == false)
            .put("transport.tcp.keep_alive", enable == false)
            .put("transport.tcp.keep_idle", "43")
            .put("transport.tcp.keep_interval", "8")
            .put("transport.tcp.keep_count", "14")
            .put("transport.tcp.reuse_address", enable == false)
            .put("transport.tcp.send_buffer_size", "5b")
            .put("transport.tcp.receive_buffer_size", "6b")