Add back the SUPL network setup timeout.

The network request timeout functionality in the ConnectivityManager
class was non functional. When it was addressed, the timeout that was
in the GnssLocationProvider class was removed as it was referring to
a constant in the ConnectivtyManager that was deleted. See b/35354391
for details.

Fixes: 35354391
Test: Tested on a Pixel device using Android Q and GNSS Test App to
      clear AGPS aiding data and doing a get GPS location for the
      following scenarios:
      1. Turned off mobile data connection but not WiFi. The cellular
         SUPL network request times out and GNSS HAL is notified of
         SUPL connection failure. GNSS HAL continues with XTRA only
         download through WiFi and completes the fix.
      2. Turned off mobile data and WiFi connections. The cellular
         SUPL network request times out and GNSS HAL is notified of
         connection failure. GNSS HAL fails to download asssistance
         data through SUPL and XTRA and reports a fix after a long
         time (several minutes).
      3. Both mobile and WiFi connections are on. GNSS HAL does
         does SUPL and XTRA requests and completes the fix.
      4. Mobile data connection is on and WiFi connection is off.
         GNSS HAL does SUPL request and completes the fix.

Change-Id: I6204c9a1b9aa4e55a91316ccc683051e847d826c