Update live-mobile-app-testing.md

[StuMinch]

Updated "Profiles & Device Management" to "VPN & Device Management"

Description

Motivation and Context

Types of Changes

• [ ] Bug fix (non-breaking change which fixes an issue)
• [ ] New feature (non-breaking change which adds functionality)
• [ ] Breaking change (fix or feature that would cause existing functionality to change)
• [ ] Documentation fix (typos, incorrect content, missing content, etc.)