Rename package from audioui to audio.ui

[luizgrp]

WHAT

Rename package name from audioui to audio.ui.

WHY

In order to have a common audio package for different layers (data, domain and ui).
I also think it was the original idea to have the name like this, based on the package name in AndroidManifest.

HOW

• Rename package from files in main, debug, and androidTest folders;

Checklist 📋

• Add explicit visibility modifier and explicit return types for public declarations
• Run spotless check
• Run tests
• Update metalava's signature text files