Add support for AWS's v2 SDK's MetricPublisher

[evg-tso]

Is your feature request related to a problem? Please describe.

Hello,
The AWS Java v2 SDK exposes metrics via the MetricPublisher interface.
I couldn't find any OTEL support for these callbacks.

Describe the solution you'd like

I'd like to contribute a PR to add an OTEL adapter to bridge the AWS callbacks.
I have a draft PR in our organization: AppsFlyer/aws-sdk-java-opentelemetry-metrics#1.
But I think that contributing to the OTEL repo is the better course of action, allowing us to align (or even define) the spec for these metrics.

Describe alternatives you've considered

No response

Additional context

No response

[trask]

cc @rapphil @wangzlei

[evg-tso]

Hi, sorry to bother you, but I'm mentioning you all again to resurface this request 🙏
@trask @rapphil @wangzlei