WKPrefersNetworkUponForeground
A Boolean value that indicates whether an app requires network access on launch.
Discussion
In low-power mode, the system turns off cellular data to preserve battery life. If this key is NO, the system waits until an app requests a network connection before turning on cellular data. This can cause a few seconds of delay before your app can perform network requests.
If your app needs access to the network immediately upon launch, set this key to YES.
WKPrefersNetworkUponForeground defaults to NO.