Register the Wifi HAL event callback again after stopping HAL.

Wifi HAL invalidates the event callback when the framework calls HAL
to stop. We still need the HAL to notify the system restart event when
Wifi is stopped.

Bug: 229199184
Bug: 227719895

Test: atest FrameworksWifiTests
Change-Id: Id482224ea340e7af24095ca27d871341a0098f97
1 file changed