Fix flaky QuartcPeerTest.BandwidthAllocationWithoutEnoughAvailable

Confirmed over 1000 runs that 11s fixes the issue for both dbg and opt, 12s gives us a bit more margin. This unblocks the v49 flag.

gfe-relnote: n/a, test-only
PiperOrigin-RevId: 271468946
Change-Id: I53ce17fa602e3f2700b31835ebd44acce76bc62f

quic/quartc/test/quartc_peer_test.cc

diff --git a/quic/quartc/test/quartc_peer_test.cc b/quic/quartc/test/quartc_peer_test.cc
index b423cd7..53a746d 100644
--- a/quic/quartc/test/quartc_peer_test.cc
+++ b/quic/quartc/test/quartc_peer_test.cc
@@ -327,7 +327,7 @@
   Connect();
 
   // Run for long enough that bandwidth ramps up to link capacity.
-  simulator_.RunFor(QuicTime::Delta::FromSeconds(10));
+  simulator_.RunFor(QuicTime::Delta::FromSeconds(12));
 
   const std::vector<ReceivedMessage>& client_messages =
       client_peer_->received_messages();