source-googlesheet: Service account json should be secret

[ChristopheDuong]

What

The service account field should be flagged as secret

Pre-merge Checklist

Expand the relevant checklist and delete the others.

• Secrets in the connector's spec are annotated with airbyte_secret
• Code reviews completed
• /test connector=connectors/<name> command is passing.
• New Connector version released on Dockerhub by running the /publish command described here
• After the connector is published, connector added to connector index as described here
• Seed specs have been re-generated by building the platform and committing the changes to the seed spec files, as described here

[ChristopheDuong]

/test connector=connectors/source-google-sheets

🕑 connectors/source-google-sheets https://github.com/airbytehq/airbyte/actions/runs/1668607149
✅ connectors/source-google-sheets https://github.com/airbytehq/airbyte/actions/runs/1668607149
Python tests coverage:

	 ---------- coverage: platform linux, python 3.8.10-final-0 -----------
	 Name                                                 Stmts   Miss  Cover
	 ------------------------------------------------------------------------
	 source_acceptance_test/__init__.py                       2      0   100%
	 source_acceptance_test/base.py                          10      4    60%
	 source_acceptance_test/config.py                        74      6    92%
	 source_acceptance_test/conftest.py                     109    109     0%
	 source_acceptance_test/plugin.py                        47     47     0%
	 source_acceptance_test/tests/__init__.py                 4      0   100%
	 source_acceptance_test/tests/test_core.py              242     96    60%
	 source_acceptance_test/tests/test_full_refresh.py       38      0   100%
	 source_acceptance_test/tests/test_incremental.py        69     38    45%
	 source_acceptance_test/utils/__init__.py                 6      0   100%
	 source_acceptance_test/utils/asserts.py                 37      2    95%
	 source_acceptance_test/utils/common.py                  54     17    69%
	 source_acceptance_test/utils/compare.py                 62     23    63%
	 source_acceptance_test/utils/connector_runner.py       110     48    56%
	 source_acceptance_test/utils/json_schema_helper.py     115     14    88%
	 ------------------------------------------------------------------------
	 TOTAL                                                  979    404    59%
	 ---------- coverage: platform linux, python 3.8.10-final-0 -----------
	 Name                                                Stmts   Miss  Cover
	 -----------------------------------------------------------------------
	 google_sheets_source/__init__.py                        2      0   100%
	 google_sheets_source/client.py                         22      5    77%
	 google_sheets_source/google_sheets_source.py          103     84    18%
	 google_sheets_source/helpers.py                       129     26    80%
	 google_sheets_source/models/__init__.py                 2      0   100%
	 google_sheets_source/models/spreadsheet.py             34      0   100%
	 google_sheets_source/models/spreadsheet_values.py      12      0   100%
	 -----------------------------------------------------------------------
	 TOTAL                                                 304    115    62%

Python short test summary info:

=========================== short test summary info ============================
SKIPPED [1] ../usr/local/lib/python3.7/site-packages/source_acceptance_test/plugin.py:56: Skipping TestIncremental.test_two_sequential_reads because not found in the config
================== 15 passed, 1 skipped in 178.86s (0:02:58) ===================

[ChristopheDuong]

/publish connector=connectors/source-google-sheets

🕑 connectors/source-google-sheets https://github.com/airbytehq/airbyte/actions/runs/1676584550
✅ connectors/source-google-sheets https://github.com/airbytehq/airbyte/actions/runs/1676584550