ZPC does not terminate upon SAPI controller device poweroff

[silabs-MarkM]

JIRA issue link

ZWAVE_SDK-2336

Commit hash

e8694

Current Behavior

When the WSTK of the SAPI controller device is powered off (either by disconnecting the USB cable, or via setting the slider switch to BAT state), the ZPC process does not terminate gracefully.

Expected Behavior

ZPC terminates gracefully (then we can restart it once the controller device is back)

Steps To Reproduce

1. start MQTT & ZPC
2. include end node (binary switch)
3. power off WSTK of SAPI controller device (disconnect the USB cable, or set the slider switch to BAT state without a connected coin cell)
4. check ZPC

Anything else?

No response