Reduce BROADCAST_TIMEOUT_MS.

We wait for a few seconds before verifying the
test app didn't receive a broadcast because it
is possible the broadcast was just delayed but
we don't necessarily have to wait for too long.

Bug: 201580811
Test: atest com.android.cts.net.HostsideRestrictBackgroundNetworkTests
Change-Id: Ie5550742c506753fc994209d4db760c1ee73a2cb
1 file changed