Implement get audio session id (Android)

[tonkarhu]

I needed to get the audio session ID created during the player initialization for further use (equalizer). Library lacked the implementation, so this is my solution for get it.

Depends on: Canardoux/flutter_sound_core#9

[tonkarhu]

This implements: GH-495

[github-actions]

This PR is stale because it has been open 90 days with no activity. Leave a comment or this will be closed in 7 days

[Larpoux]

@tonkarhu : First, I am very sorry that I did not look to your PR sooner.
Your PR seems very good. I am going to merge it in the last Flutter Sound version.
I just hope that you have not switched to another Flutter Plugin because I was too late to integrate your PR into Flutter Sound.

I am very impressed that you was able to develop on flutter_sound_core : it is something not very easy because the library is not hosted on pub.dev. Congratulations.

[Larpoux]

Hi @tonkarhu .

Flutter Sound does not manage the Audio Sessions. The Audio Sessions are handled by (The Audio_Session Pluggin)[https://pub.dev/packages/audio_session].