VBLOCKS-3834 Make AudioDeviceChangeListener optional parameter when calling start()

[ocarevs]

Description

Make AudioDeviceChangeListener optional parameter when calling start()

Breakdown

• AudioDeviceChangeListener parameter when calling AudioSwitch.start() can be omitted or be null in java case.
• Adding AudioSwitch.addAudioDeviceChangeListener(listener: AudioDeviceChangeListener) to add listener in case the listener was not passed when calling start()
• Adding AudioSwitch.removeAudioDeviceChangeListener() to remove existing listener.

Validation

• Unit tests

Additional Notes

[Any additional comments, notes, or information relevant to reviewers.]

Submission Checklist

• The source has been evaluated for semantic versioning changes and are reflected in gradle.properties
• The CHANGELOG.md reflects any feature, bug fixes, or known issues made in the source code

[afalls-twilio]

Make set auduio device listener take null to unset