[AIRFLOW-5679][WIP] Rename GoogleCloudStorageHook to GcsHook

[michalslowikowski00]

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[codecov-io]

Codecov Report

Merging #6412 into master will decrease coverage by 0.45%.
The diff coverage is 87.09%.

@@            Coverage Diff             @@
##           master    #6412      +/-   ##
==========================================
- Coverage   80.61%   80.16%   -0.46%     
==========================================
  Files         626      626              
  Lines       36224    36228       +4     
==========================================
- Hits        29203    29042     -161     
- Misses       7021     7186     +165

Impacted Files	Coverage Δ
airflow/utils/log/gcs_task_handler.py	0% <0%> (ø)	⬆️
airflow/operators/cassandra_to_gcs.py	63.31% <100%> (ø)	⬆️
airflow/gcp/hooks/gcs.py	84.98% <100%> (ø)	⬆️
airflow/operators/gcs_to_gcs.py	95.65% <100%> (ø)	⬆️
airflow/gcp/operators/dataflow.py	99.07% <100%> (ø)	⬆️
...e/marketing_platform/operators/campaign_manager.py	91.73% <100%> (ø)	⬆️
airflow/gcp/operators/text_to_speech.py	100% <100%> (ø)	⬆️
airflow/operators/adls_to_gcs.py	97.72% <100%> (ø)	⬆️
...irflow/contrib/operators/gcs_to_gdrive_operator.py	100% <100%> (ø)	⬆️
airflow/contrib/operators/s3_to_gcs_operator.py	86.44% <100%> (ø)	⬆️
... and 26 more

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[mik-laj]

If we use shortcuts, we should write them Capitalized e.g. GKE, GCS

https://docs.google.com/document/d/1_rTdJSLCt0eyrAylmmgYc3yZr-_h51fVlnvMmWqhCkY/edit?ts=5bb72dfd#

We need to update our planned changes

[mik-laj]

Can you also update a note in UPDATING.md file?
https://github.com/apache/airflow/blob/master/UPDATING.md#changes-to-import-paths-and-names-of-gcp-operators-and-hooks

[michalslowikowski00]

@mik-laj So the GCSHook will be the correct name?