[appID] Use Default Media Receiver when setting appID to 'default'

[youzi]

When passing 'default'as the appID, I'd like the plugin to use the default media receiver app id, which differs per platform. This will enable us to test easily our sender apps without registering new applications/receivers.

From the docs: https://developers.google.com/cast/docs/receiver_apps :

Default Media Receiver

A third option available is the Default Media Receiver. This is a pre-built receiver application hosted by Google that is designed for streaming your audio and video content. It does not require you to register with the Google Cast SDK Developer Console, but you cannot customize any of the UI in the Default Media Receiver.

Instead of registering with the developer console to receive an app ID, you can use the Default Media Receiver with the default app ID:

For Android apps: CastMediaControlIntent.DEFAULT_MEDIA_RECEIVER_APPLICATION_ID
For Chrome apps: chrome.cast.media.DEFAULT_MEDIA_RECEIVER_APP_ID
For iOS apps: kGCKMediaDefaultReceiverApplicationID
From your sender app, you start the Default Media Receiver app on the Cast device and then use it to load the URL to your media.

So for web use: chrome.cast.media.DEFAULT_MEDIA_RECEIVER_APP_ID
For android use: CastMediaControlIntent.DEFAULT_MEDIA_RECEIVER_APPLICATION_ID
And for iOS use: kGCKMediaDefaultReceiverApplicationID

/cc @vigour-io/native

[renancarvalho]

I know how to do it! I'll do it tomorrow :)

[shawninder]

I guess we have two choices:

1. Each platform could have a static var with the appropriate id + a simple check if (appId === 'default') { appdId = defaultId } in its native code.
2. The alternative being to handle this in the js, meaning the js side would need to know the ids of each platform (not a big problem either).

I guess I have a slight preference for #1 (one less if), but I can't really give convincing arguments either way...