Add uid to the failure log of testFirewallBlocking

ConnectivityManagerTest#testFirewallBlockingXXX were flaky.
One possibility of making this test flaky is that somehow the test was
running with system uid.
So this CL adds uid to the failure log.

Test: m
Bug: 276496378
Change-Id: Iae1a0fe2ee8311213091e852fb1be9233cc3db56
1 file changed