Add Continuous Profiling support

[stefanosiano]

📜 Description

This is the first part for the continuous profiling support for Android.
Internal doc is here

Part 1
Add the implementation of the continuous profiler itself

Part 2 -> #3695
Create new envelope type and payload
Create and send profile_chunk envelope

Part 3
Instantiate profiler
Set ProfileContext to transactions and spans
Add performance collectors to the profiler

Part 4
Handle app start profiling

Part 5
Add new user-facing APIs

Part 6
Update docs

💡 Motivation and Context

💚 How did you test it?

Unit tests

📝 Checklist

• I reviewed the submitted code.
• I added tests to verify the changes.
• No new PII added or SDK only sends newly added PII if sendDefaultPII is enabled.
• I updated the docs if needed.
• Review from the native team if needed.
• No breaking change or entry added to the changelog.
• No breaking change for hybrid SDKs or communicated to hybrid SDKs.

🔮 Next steps

[github-actions]

	Fails
🚫	Please consider adding a changelog entry for the next release.

	Messages
📖	Do not forget to update Sentry-docs with your feature once the pull request gets approved.

Instructions and example for changelog

Please add an entry to CHANGELOG.md to the "Unreleased" section. Make sure the entry includes this PR's number.

Example:

## Unreleased

- Add Continuous Profiling support ([#3683](https://github.com/getsentry/sentry-java/pull/3683))

If none of the above apply, you can opt out of this check by adding #skip-changelog to the PR description.

Generated by 🚫 dangerJS against d7d846f

[github-actions]

Performance metrics 🚀

	Plain	With Sentry	Diff
Startup time	415.65 ms	429.72 ms	14.07 ms
Size	1.70 MiB	2.35 MiB	660.81 KiB

[stefanosiano]

Closing in favor of #3710