The GCSToLocalFilesystemOperator in Google Provider <=3.0.0  had wrong import for apply_defaults. It used

```
from airflow.sensors.base_sensor_operator import apply_defaults
```

instead of 

```
from airflow.utils.decorators import apply_defaults
```

When we removed `apply_defaults` in #15667, the base_sensor_operator import was removed as well which made the GCSToLocalFilestystemOperator stops working in 2.1.0

The import in base_sensor_operator will be restored in 2.1.1  and Google Provider 4.0.0 will work without problems after it is released. Workaround for 2.1.0 Airflow is to copy the code of the operator to DAG and use it temporarily until new versions are released. 
airflow/sensors/base.py
'poke_interval',
        'retries',
        'execution_timeout',
        'timeout',
        'email',
        'email_on_retry',
        'email_on_failure',
    )
    def __init__(
        self,
        *,
        poke_interval: float = 60,
        timeout: float = 60 * 60 * 24 * 7,
        soft_fail: bool = False,
        mode: str = 'poke',
        exponential_backoff: bool = False,
        **kwargs,
    ) -> None:
        super().__init__(**kwargs)
        self.poke_interval = poke_interval
        self.soft_fail = soft_fail
        self.timeout = timeout
        self.mode = mode
        self.exponential_backoff = exponential_backoff
        self._validate_input_values()
        self.sensor_service_enabled = conf.getboolean('smart_sensor', 'use_smart_sensor')
        self.sensors_support_sensor_service = set(
            map(lambda l: l.strip(), conf.get('smart_sensor', 'sensors_enabled').split(','))
        )
    def _validate_input_values(self) -> None: