remove passing component property when route is not instrumented

[vigneshshanmugam]

• When the component property is not instrumented via <ApmRoute> component, we should not override the props passed down to Route component. This creates a memory leak warning in React and also its a bug in general.

https://github.com/elastic/apm-agent-rum-js/blob/master/packages/rum-react/src/get-apm-route.js#L36

Found this while instrumenting Kibana

[vigneshshanmugam]

After double checking, ruled out that this is not the source of the memory leak warning that gets logged. the component property would be undefined which would be ignored by React Route component.