**Apache Airflow version**: 2.1.0


**Environment**:

- **Cloud provider or hardware configuration**:
- **OS** (e.g. from /etc/os-release):
- **Kernel** (e.g. `uname -a`):
- **Install tools**:
- **Others**:

**What happened**:  FileSensor does not recognize directories with wildcard glob matching.

**What you expected to happen**: FileSensor would sense a directory that contains files if it matches with the wild card option.

**How to reproduce it**: Create a directory with a pattern that matches a wild card using glob



**Anything else we need to know**: Code from FileSensor source that I believe to cause the issue:

```
for path in glob(full_path):
            if os.path.isfile(path):
                mod_time = os.path.getmtime(path)
                mod_time = datetime.datetime.fromtimestamp(mod_time).strftime('%Y%m%d%H%M%S')
                self.log.info('Found File %s last modified: %s', str(path), str(mod_time))
                return True

            for _, _, files in os.walk(full_path):
                if len(files) > 0:
                    return True
        return False

```
I believe to resolve the issue `full_path` in os.walk should be `path` instead.


tests/sensors/test_filesystem.py
temp_dir = tempfile.mkdtemp()
        task = FileSensor(
            task_id="test",
            filepath=temp_dir[1:],
            fs_conn_id='fs_default',
            dag=self.dag,
            timeout=0,
        )
        task._hook = self.hook
        try:
            
            open(temp_dir + "/file", "a").close()
            task.run(start_date=DEFAULT_DATE, end_date=DEFAULT_DATE, ignore_ti_state=True)
        finally:
            shutil.rmtree(temp_dir)
    def test_default_fs_conn_id(self):