bluetooth autotest: Fix service name in debug_log_levels()

Debug logs are only implemented in btdispatch, therefore this patch
sets the value directly, as opposed to evaluate it based on the status
of newblue.

After Debug logs is migrated to bluez, we should also re-update this
part of the code.

BUG=b:145749798
TEST=Run quick sanity, ensure there are some logs with the format
     <timestamp> DEBUG bluetoothd[<pid>]: <file>:<some_message>
     in /var/log/messages

Change-Id: Ibf513c9b941cea044128a2ca04384fca08db79be
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/third_party/autotest/+/1956443
Reviewed-by: Daniel Winkler <danielwinkler@google.com>
Commit-Queue: Archie Pusaka <apusaka@chromium.org>
Tested-by: Archie Pusaka <apusaka@chromium.org>
diff --git a/client/cros/bluetooth/bluetooth_device_xmlrpc_server.py b/client/cros/bluetooth/bluetooth_device_xmlrpc_server.py
index e7df47c..90f0f8a 100755
--- a/client/cros/bluetooth/bluetooth_device_xmlrpc_server.py
+++ b/client/cros/bluetooth/bluetooth_device_xmlrpc_server.py
@@ -201,8 +201,11 @@
         @param kernel_vb: verbosity of kernel debug log, either 0 or 1
 
         """
+
+        # TODO(b/145163508, b/145749798): update when debug logs is migrated to
+        #                                 bluez.
         debug_object = self._system_bus.get_object(
-                                                self._bluetooth_service_name,
+                                                self.BLUETOOTH_SERVICE_NAME,
                                                 self.BLUEZ_DEBUG_LOG_PATH)
         debug_object.SetLevels(dbus.Byte(dispatcher_vb),
                                dbus.Byte(newblue_vb),