Improve forwarder2 setup/tear down in telemetry.

build/android/bb_run_sharded_steps.py

Index: build/android/bb_run_sharded_steps.py
diff --git a/build/android/bb_run_sharded_steps.py b/build/android/bb_run_sharded_steps.py
index 7a06155b137c8534adcc5030489160bb0cb3c3f8..afd354a32e2e916857c28e642d5d4409178849dd 100755
--- a/build/android/bb_run_sharded_steps.py
+++ b/build/android/bb_run_sharded_steps.py
@@ -58,6 +58,7 @@ import sys
 from pylib import android_commands
 from pylib import cmd_helper
 from pylib import constants
+from pylib import forwarder
 from pylib import ports
 
 
@@ -164,6 +165,7 @@ def _PrintAllStepsOutput(steps):
 
 def _KillPendingServers():
   for retry in range(5):
+    forwarder.Forwarder.KillHost()
     for server in ['lighttpd', 'web-page-replay']:
       pids = cmd_helper.GetCmdOutput(['pgrep', '-f', server])
       pids = [pid.strip() for pid in pids.split('\n') if pid.strip()]