Automatically add /v1/metrics to endpoints

[tkennedy1-godaddy]

Is your feature request related to a problem?

In other otel libraries (go and javascript), when you provide an endpoint the library will automatically append /v1/metrics to it. This has cause some confusion on our teams as to how to properly provide endpoints.

(This has been previously reported as a bug in #3200)

Describe the solution you'd like

If /v1/metrics is missing from the endpoint, it should be added.

Describe alternatives you've considered

n/a

Additional Context

Ideally the otel libraries should work similarly to each other to help prevent confusion

Would you like to implement a fix?

Yes