Audio Driver Service using singleton design pattern

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Implement the design of audio system of a device.

various applications (installed on the device) that need access to speaker hardware of the device for their features to work.

AudioDriverService which provides the following functionalities

• Initializes the hardware.
• Initializes the I/O engine and stops and starts it.
• Attach and detach the I/O engine to Audio Stream and Audio Control objects .
• Respond to value changes in the AudioControl object. (ex: volume increase/decrease, bass increase/decrease etc)

Only one application should get access to the hardware at any given point in time. Examples for applications: Windows Media Player, Youtube, VLC player.

No need to implement the functions, need empty dummy functions.