AudioAttributes - class encapsulating information about the audio stream

main params
    - usage - like USAGE_MEDIA, USAGE_ALARM etc.
    - content type - like CONTENT_TYPE_MOVIE, CONTENT_TYPE_MUSIC



@ServiceScoped
@Provides
fun providesAudioAttributes() = AudioAttributes.Builder()
    .setContentType(C.CONTENT_TYPE_MUSIC)
    .setUsage(C.USAGE_MEDIA)
    .build()




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Exoplayer - the thing which will be actually palying the music

Needs
- Application Context
- AudioAttributes

@ServiceScoped
@Provides
fun providesExoPlayer(@ApplicationContext context: Context, audioAttributes: AudioAttributes) = Exoplayer.Builder(context).build.apply {
    setAudioAttributes(audioAttributes, true),
    setHandleAudioBecomingNoisy(true)
    }


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DataSourceFactory - Firebase wil be our data source

@ServiceScoped
@Provides
fun providesDataSourceFactory(@ApplicationContext context: Context) = DefaultDataSource.Factory(context)