Expose AVAudioSession interface

[ajsharp]

Is your feature request related to a problem? Please describe.
I need access to the AVAudioSession swift class. This is useful and necessary sometimes, such as when connected to a car bluetooth device to "end the call" that cars will "start" when you are using the mic when in the car.

Describe the solution you'd like
Make a method available that allows setting the AVAudioSession category.

[llfbandit]

This package won't expose this.
What can be done is to restore the previous category before the recording.

[mynlexi]

This is also quite a big painpoint for our project

[bbjay]

There is a new option IosRecordConfig.manageAudioSession (in master, but not yet released) which you can set to false and then use the audio_session plugin to manage the AVAudioSession all by yourself.

[llfbandit]

manageAudioSession & category options ref: d25e64c 8485404