The YouTube Player Integration uses the Youtube Android Player API
which requires an API key to work. You can get yourself an API key from creating an account at
console.cloud.google.com and set the YOUTUBE_API_KEY in your local.properties
file (which shouldn't be pushed to the repo).
The YOUTUBE_API_KEY is then accessible through BuildConfig.YOUTUBE_API_KEY in the code using the
com.google.android.secrets-gradle-plugin gradle plugin. We also have the local.defaults.properties
(which is pushed to the repo with "PLACE_HOLDER" values so we can get a BuildConfig.YOUTUBE_API_KEY.