support passing credentials from memory for google connectors (#1888)
### Description
### Google Drive
The existing service account parameter was expanded to support either a
file path or a json value to generate the credentials when instantiating
the google drive client.
### GCS
Google Cloud Storage already supports the value being passed in, from
their docstring:
> - you may supply a token generated by the
[gcloud](https://cloud.google.com/sdk/docs/)
utility; this is either a python dictionary, the name of a file
containing the JSON returned by logging in with the gcloud CLI tool,
or a Credentials object.
I tested this locally:
```python
from gcsfs import GCSFileSystem
import json
with open("/Users/romanisecke/.ssh/google-cloud-unstructured-ingest-test-d4fc30286d9d.json") as json_file:
json_data = json.load(json_file)
print(json_data)
fs = GCSFileSystem(token=json_data)
print(fs.ls(path="gs://utic-test-ingest-fixtures/"))
```
`['utic-test-ingest-fixtures/ideas-page.html',
'utic-test-ingest-fixtures/nested-1',
'utic-test-ingest-fixtures/nested-2']`
unstructured
123ad20f - support passing credentials from memory for google connectors (#1888)
