OTLP examples are inconsistent in the use of endpoint url

[ramgdev]

Currently, the examples in opentelemetry-otlp project are using two different ways to specify the endpoint URL. basic-otlp is setting the endpoint url without the signal specific path http://localhost:4317 and still works. However, the example in basic-otlp-http is setting the endpoint with the signal specific path http://localhost:4318/v1/traces. If the signal specific path /v1/traces is removed, the example fails to run whereas basic-otlp works either way.

This brings up the question of whether the SDK should default signal specific path when there is no path specified in the endpoint URL. Given the spec already refers to default path for each signal, it would serve SDK consumers not to bother about them when setting the endpoint URL when configuring the respective providers/exporters. In other words, the example in basic-otlp-http should work the same way as basic-otlp currently works as of version 0.27.0.

[cijothomas]

@lalitb will you be able to check this one?