Avoid including device name in adb command if it is empty.

PiperOrigin-RevId: 662172728

android_env/components/adb_controller.py

@@ -54,7 +54,7 @@ def command_prefix(self, include_device_name: bool = True) -> list[str]:
         '-P',
         str(self._config.adb_server_port),
     ]
-    if include_device_name:
+    if include_device_name and self._config.device_name:
       command_prefix.extend(['-s', self._config.device_name])
     return command_prefix