Creating an android app that acts as an A2DP sink for other devices to stream media to

Question

I have an old phone that I am trying to repurpose by making it into a bluetooth receiver for audio + a Google Assistant voice search device. Its a Moto G1 2013 (XT1033) running Android 5.1.1

I want to create an app that makes the phone receive audio via bluetooth from other media sources (my laptop, other phones and so on) and play it through the headphone jack. Google assistant will run in the background connected to my main Google account and would play music through Spotify etc.

Would appreciate help so I can get this app running!

I am relatively new to Android app development and did not understand what the answers to other similar questions meant. Here are a few links: Android device as a receiver for A2DP profile How to enable android bluetooth a2dp sink and play music on android L https://github.com/aystshen/Android-A2dpSink http://opensource.hcltechsw.com/volt-mx-native-function-docs/Android/android.bluetooth-Android-10.0/index.html#!/api/android.bluetooth.BluetoothA2dpSink

I did not understand where to add these commands: in the Manifest? Did not seem to work. I also did not understand how the Android API supports this as there is no mention of this feature.