Playing Spotify on the web does not work

[gcampax]

Failed to play Spotify CustomError: No player is available to complete this request
    at AudioController.requestAudio (/opt/almond-cloud/node_modules/genie-toolkit/dist/lib/dialogue-agent/audio/controller.js:181:19)
    at SpotifyDevice.player_play_helper (/srv/thingengine/b428c7ce0d134f04/cache/device-classes/com.spotify/index.js:1210:37)
    at SpotifyDevice._flushPlay (/srv/thingengine/b428c7ce0d134f04/cache/device-classes/com.spotify/index.js:1308:14)
    at /srv/thingengine/b428c7ce0d134f04/cache/device-classes/com.spotify/index.js:993:28
    at ExecWrapper.exitProcedure (/opt/almond-cloud/node_modules/genie-toolkit/dist/lib/engine/apps/exec_wrapper.js:191:19)
    at runMicrotasks (<anonymous>)
    at processTicksAndRejections (internal/process/task_queues.js:97:5)
    at async eval (eval at compile (/opt/almond-cloud/node_modules/thingtalk/dist/compiler/jsir.js:786:46), <anonymous>:67:5)
    at async RuleExecutor._ruleThread (/opt/almond-cloud/node_modules/genie-toolkit/dist/lib/engine/apps/rule_executor.js:61:13) {
  code: 'unsupported'
}

This is because the command comes from a conversation that has no AudioPlayer support in the AudioController. In that case, we should track the audio state using the old logic (calling only into the interface), knowing that Spotify will play out of band.