Change default OpenTelemetry protocol to http/protobuf

[brunobat]

Description

The default OTLP protocol must be changed from grpc to http/protobuf in order to align with the specification.

There is something wrong with the span exporter when we change the protocol and the fix is too complex for #41521

Implementation ideas

No response

[quarkus-bot]

/cc @radcortez (opentelemetry)

[geoand]

So I assume we need #41521 in first?

[brunobat]

Yes we do and #39032 as well, preferably.

[geoand]

👌

[jorsol]

Isn't gRPC generally more performant than HTTP/Protobuf?

Or is this change simply to adjust the default, which can still be explicitly configured to use gRPC if desired?

[brunobat]

It is to adjust with the upstream default, @jorsol. It is was moved to HTTP and we should align.
gRPC will still be available and I don't plan to implement the change anytime soon.