[Telemetry] Make prebuilt binary installation a little more robust.

tools/telemetry/telemetry/unittest/system_stub.py

Index: tools/telemetry/telemetry/unittest/system_stub.py
diff --git a/tools/telemetry/telemetry/unittest/system_stub.py b/tools/telemetry/telemetry/unittest/system_stub.py
index 0e9511d8114b8d73ae103556a3d7b84ce9bac281..de629bc1463e01295df508e167f00cc95163c345 100644
--- a/tools/telemetry/telemetry/unittest/system_stub.py
+++ b/tools/telemetry/telemetry/unittest/system_stub.py
@@ -67,6 +67,9 @@ class AdbCommandsModuleStub(object):
     def IsRootEnabled(self):
       return self.is_root_enabled
 
+    def RestartAdbdOnDevice(self):
+      pass
+
   def __init__(self):
     self.attached_devices = []
     self.shell_command_handlers = {}
@@ -86,6 +89,9 @@ class AdbCommandsModuleStub(object):
   def HasForwarder(_=None):
     return True
 
+  def SetupPrebuiltTools(self, _):
+    return True
+
 
 class CloudStorageModuleStub(object):
   INTERNAL_BUCKET = None
@@ -227,7 +233,7 @@ class SubprocessModuleStub(object):
     self.PIPE = None
 
   def call(self, *args, **kwargs):
-    raise NotImplementedError()
+    pass
 
 
 class SysModuleStub(object):