### Official Helm Chart version

1.2.0

### Apache Airflow version

2.1.4

### Kubernetes Version

v1.21.6+bb8d50a

### Helm Chart configuration

I defined a new Connection String for AIRFLOW_CONN_SPARK_DEFAULT in values.yaml like the following section (base64 encoded or with correct string (spark://k8s://100.68.0.1:443?deploy-mode=cluster):

```
extraSecrets:
  '{{ .Release.Name }}-airflow-connections':
     data: |
       AIRFLOW_CONN_SPARK_DEFAULT: 'c3Bhcms6Ly9rOHM6Ly8xMDAuNjguMC4xOjQ0Mz9kZXBsb3ktbW9kZT1jbHVzdGVy'
```

in Section extraEnvFrom i defined the following:

```
extraEnvFrom: |
   - secretRef:
       name: '{{ .Release.Name }}-airflow-connections'
```

### Docker Image customisations

added apache-airflow-providers-apache-spark to base Image

### What happened

Airflow Connection mapped wrong because of the k8s:// within the url.  if i ask for the connection with cmd "airflow connections get spark_default" then host=k8s and schema=/100.60.0.1:443 which is wrong

### What you expected to happen

the spark Connection based on k8s (spark://k8s://100.68.0.1:443?deploy-mode=cluster) should be parsed correctly

### How to reproduce

define in values.yaml

```
extraSecrets:
  '{{ .Release.Name }}-airflow-connections':
     data: |
       AIRFLOW_CONN_SPARK_DEFAULT: 'c3Bhcms6Ly9rOHM6Ly8xMDAuNjguMC4xOjQ0Mz9kZXBsb3ktbW9kZT1jbHVzdGVy'

extraEnvFrom: |
   - secretRef:
       name: '{{ .Release.Name }}-airflow-connections'
```


### Anything else

_No response_

### Are you willing to submit PR?

- [ ] Yes I am willing to submit a PR!

### Code of Conduct

- [X] I agree to follow this project's [Code of Conduct](https://github.com/apache/airflow/blob/main/CODE_OF_CONDUCT.md)

"""
        Here we verify that ``extra`` is a JSON-encoded Python dict.  From Airflow 3.0, we should no
        longer suppress these errors but raise instead.
        """
        if extra is None:
            return None
        try:
            extra_parsed = json.loads(extra)
            if not isinstance(extra_parsed, dict):
                warnings.warn(
                    "Encountered JSON value in `extra` which does not parse as a dictionary in "
                    f"connection {conn_id!r}. From Airflow 3.0, the `extra` field must contain a JSON "
                    "representation of a Python dict.",
                    RemovedInAirflow3Warning,
                    stacklevel=3,
                )
        except json.JSONDecodeError:
            warnings.warn(
                f"Encountered non-JSON in `extra` field for connection {conn_id!r}. Support for "
                "non-JSON `extra` will be removed in Airflow 3.0",
                RemovedInAirflow3Warning,
                stacklevel=2,
            )
        return None
    @reconstructor
    def on_db_load(self):
        if self.password:
            mask_secret(self.password)
    def parse_from_uri(self, **uri):