Add Audio Concurrency Test Cases

[tmoida]

Problem

Currently we have 10 test configurations each for AudioPlayback and AudioRecord. These tests run independently and don't cover scenarios where multiple audio operations happen at the same time.

Proposed Solution

Add concurrency test cases for:

1. Playback + Playback - Two simultaneous audio playback operations
2. Playback + Record - Simultaneous audio playback and recording

Implementation Tasks

• Define test configuration matrix
• Create YAML files for Playback+Playback scenarios
• Create YAML files for Playback+Record scenarios
• Write run.sh scripts for concurrent execution
• Update documentation

Success Criteria

• Both operations complete without errors
• No audio artifacts or quality issues
• No kernel errors in dmesg
• Proper .res file generation for CI/CD