🐛 [firestore-bigquery-export] Root collection wildcard regression

### Configuration

- Extension name: `firestore-bigquery-export`
- Extension version: 0.2.2
- Configuration values (redact info where appropriate):
- collection: `{collection}`

#### Steps to reproduce:

1. Install the extension while trying to use a global collection wildcard `{collection}`

##### Expected result

Extension deploys successfully

##### Actual result

Extension deploy fails with the following error

```
failed to startDeploymentManagerWork for instance id: firestore-bigquery-export, parentId: my-project-id: error updating deployment for "projects/my-project-id/global/deployments/firestore-bigquery-export" with delete policy "ABANDON": generic::internal: DM HTTP 412 error. Body: { "error": { "code": 412, "message": "Error parsing configuration: while parsing a block mapping\n in 'string', line 71, column 19:\n - attribute: document\n ^\nexpected \u003cblock end\u003e, but found '\u003cscalar\u003e'\n in 'string', line 73, column 38:\n ... value: {collection}/{documentId}\n ^\n", "errors": [ { "message": "Error parsing configuration: while parsing a block mapping\n in 'string', line 71, column 19:\n - attribute: document\n ^\nexpected \u003cblock end\u003e, but found '\u003cscalar\u003e'\n in 'string', line 73, column 38:\n ... value: {collection}/{documentId}\n ^\n", "domain": "global", "reason": "conditionNotMet", "location": "If-Match", "locationType": "header" } ] } }
```

This was previously working as expected before i updated to 0.2.2