Is First Run On Device

[winsmith]

Based on the sheer number of people asking me about this every time I post this graph, it might be worth automatically adding some kind of simple "isFirstRunOnDevice" flag on all logs into the SDK

• Gate this code so it only runs on platforms which du supply a UserDefault implementation
• Check if com.telemetrydeck.[APP_ID].hasInitializedBefore is set (replace [APP ID] with the app's ID. If it is not set, set it to true.
• On Signal send, add a payload value with key "isFirstRunOnDevice" and value either "true" or "false"