I couldn't find the component for QtSystems.

Destroying an object connected to QBatteryInfo calls `QBatteryInfo::disconnectNotify` which calls isSignalConnected. However, disconnectNotify documentation is very clear: it cannot call QObject methods that locks the QObject mutex, such as isSignalConnected.

This causes a deadlock when the connected QObject shares the same QMutex with the QBatteryInfo object.

It is easy to reproduce by resizing the _q_ObjectMutexPool size to 1.

Tested on Linux, but should also be the case on Windows and Android.

Tested with Qt 5.12.8, but should also be the case on Qt5.15 and Qt6 if QtSystems is ported.