@Retention(value=SOURCE)
public static @interface LockScreenConfig.DisplayMode
DISPLAY_MODE_NEVER - The lock screen should never be shown. This should almost always mean that you will build your own lock screen.
DISPLAY_MODE_REQUIRED_ONLY - The lock screen should only be shown when it is required by the head unit.
DISPLAY_MODE_OPTIONAL_OR_REQUIRED - The lock screen should be shown when required by the head unit or when the head unit says that
its optional, but *not* in other cases, such as before the user has interacted with your app on the head unit.
DISPLAY_MODE_ALWAYS - The lock screen should always be shown after connection.