Integrate Telnyx Voice In bass44 app

My Bass44 Android app already handles user accounts and general telephony UI, but the voice channel itself still relies on a placeholder SIP stack. I now want to swap that out and connect directly to Telnyx so users can place and receive real calls from inside the app.

Here is what I need from you:
• Wire the Telnyx voice-calling SDK or raw SIP/WebRTC endpoints into the existing Android codebase.
• Implement secure authentication with my Telnyx account, handle inbound and outbound call flows, and expose simple callbacks so my UI can update on ringing, answered, muted, held, and ended states.
• Provide brief build/run documentation plus any configuration files required for future environments.

I will share the current repository and my Telnyx credentials once we agree on scope. When you respond, please point me to past work—links, APKs, or repos—where you have done similar VoIP or Telnyx/Twilio/SIP integrations on Android. That evidence will be the main factor in my selection.

Acceptance is straightforward: I can install the debug build, tap “Call”, hear the remote phone ring, answer from another device, talk for at least 30 seconds with clear audio in both directions, and see the call gracefully terminate without crashes or lingering audio threads.