ES GCS encryption repository plugin v 2.1.0

Switch to GoogleCredentials instead of UserCredentials, to support all
credentials settings for GCS

ES GCS encryption repository plugin v 2.0.0

Existing properties for Aiven GCS client are in conflict with ES GCS plugin.
As result all aiven gcs client settings from now on have prefix aiven.

ES GCS encryption repository plugin v 1.0.1

ES 8.7.1 support

ES GCS encryption repository plugin v 1.0.0

Elasticsearch GCS encryption repository plugin with zstd support