Android Lock Screen Music Controls -- 2

I need a developer who can wire proper play / pause as well as previous-next buttons into my existing Android app so that they appear on the lock screen and in the pull-down notification shade (just under the Wi-Fi and other system icons). The media involved is music only—no video or podcast handling is necessary—so you can focus on a clean MediaSession implementation.

The notification tab should let users control music playback directly; no extra settings tiles or album art tweaks are required, the default visual style is fine. My current build is already functional inside the app, I just haven’t been able to surface those controls outside it. All work must remain compatible from Android 8.0 upward.

Please deliver:
• Updated Kotlin/Java code (or clear patches) that registers the MediaSession, builds the notification with playback actions, and updates metadata correctly.
• Any required manifest tweaks and pro-guard rules.
• A short README so I can reproduce the build and understand key changes.

If you can solve the lock-screen integration cleanly and test it on at least two recent Android versions, let’s get started right away.