bluetooth: Extend advertising time in advmon combination tests

When BlueZ starts discovery, it initiates a 5 seconds break for every
10.24 seconds discovery. test_device_found failed if the break and peer
advertisement happened at the same time.

BUG=b:176511118
TEST=none

Change-Id: I6f6a3bf8ff47b0b91afd214611ea675212d042e2
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/third_party/autotest/+/2605376
Reviewed-by: Archie Pusaka <apusaka@chromium.org>
Commit-Queue: Yun-Hao Chung <howardchung@google.com>
Tested-by: Yun-Hao Chung <howardchung@google.com>
diff --git a/server/cros/bluetooth/bluetooth_adapter_adv_monitor_tests.py b/server/cros/bluetooth/bluetooth_adapter_adv_monitor_tests.py
index e07c6ad..67ca692 100644
--- a/server/cros/bluetooth/bluetooth_adapter_adv_monitor_tests.py
+++ b/server/cros/bluetooth/bluetooth_adapter_adv_monitor_tests.py
@@ -1655,7 +1655,7 @@
 
         # DeviceFound should get triggered for keyboard.
         self.test_reset_event_count(monitor1)
-        self.test_start_peer_device_adv(self.peer_keybd, duration=5)
+        self.test_start_peer_device_adv(self.peer_keybd, duration=10)
         self.test_device_found(monitor1, count=self.MULTIPLE_EVENTS)
         self.test_stop_peer_device_adv(self.peer_keybd)