Fix BLE commissioning. (#11805)

While fixing network commissioning I broke BLE. Sorry.

Underlying issue - BLE and IP commissioning both do network adds
incorrectly. BLE uses the PASE connection and handles the network
add in chip-tool. IP uses the CASE connection after commissioning.
Neither are fully spec compliant, but we need to merge the BLE and
IP commissioning flows to get chip-tool to work in a spec-compliant
way in both cases.

src/controller/CHIPDeviceController.cpp

@@ -938,7 +938,7 @@ void DeviceCommissioner::RendezvousCleanup(CHIP_ERROR status)
 {
  FreeRendezvousSession();
 
- if (mDeviceBeingCommissioned != nullptr)
+ if (mDeviceBeingCommissioned != nullptr && mIsIPRendezvous)
  {
  // Release the commissionee device. For BLE, this is stored,
  // for IP commissioning, we have taken a reference to the