Add to_json method to ExponentialHistogram

[rbtz-openai]

Description

This fixes console exporter for ExponentialHistogram.

Fixes #3579

Type of change

• Bug fix (non-breaking change which fixes an issue)

Does This PR Require a Contrib Repo Change?

• Yes. - Link to PR:
• No.

Checklist:

• Followed the style guidelines of this project
• Changelogs have been updated
• Unit tests have been added
• Documentation has been updated

[linux-foundation-easycla]

The committers listed above are authorized under a signed CLA.

• ✅ login: rbtz-openai / name: Alexey Ivanov (3f67ec9, 6968f15, ba090dd, 4aecf46)
• ✅ login: lzchen / name: Leighton Chen (465b295)
• ✅ login: pmcollins / name: Pablo Collins (15b10d1)

[xrmx]

It would be nice to add a test while you are at it

[rbtz-openai]

It would be nice to add a test while you are at it

I did not find a good existing place for exporter tests. Would a console exporter's integration test suffice?

[rbtz-openai]

@xrmx is it changelog worthy, or should we just add "Skip Changelog"?

[xrmx]

@xrmx is it changelog worthy, or should we just add "Skip Changelog"?

Since this is user visible I think it'll be good to have it recorded in the Changelog

[rbtz-openai]

@xrmx can you please kick off the tests?

[xrmx]

@xrmx can you please kick off the tests?

Sorry, I don't have enough powers

[rbtz-openai]

@pmcollins when you have a second, can you please kick off the tests, and maybe merge if it looks good?

[rbtz-openai]

@pmcollins can you please add the "Skip Public API check" label?

Currently the check thinks that:

The code in this branch removes the following public symbols:

- opentelemetry-sdk/src/opentelemetry/sdk/environment_variables.py
	OTEL_SDK_DISABLED

even though i did not touch that code.

[rbtz-openai]

@pmcollins a friendly ping =) (and maybe @srikanthccv)

[pmcollins]

Thank you for your patience :). Can you fix lint @rbtz-openai ?

[rbtz-openai]

Updated, now it passes:

python scripts/eachdist.py lint --check-only

But, sadly, fails publicAPICheck

[pmcollins]

Nice. That failure appears to be unrelated -- we'll have to chase it down separately.