Remove deprecated storage schema api feature flag and relevant integration tests
The following endpoints are currently driven by feature flag "schema_endpoints_disabled". MR (!251 (merged))
- POST endpoint(/api/storage/v2/schema) in storage service.
- GET endpoint(/api/storage/v2/schema) in storage service
- DELETE endpoint(/api/storage/v2/schema) in storage service
- GET endpoint(/api/storage/v2/query/kinds) in storage service
When the feature flag is removed please ensure to also update integration tests to fix/remove any tests that are using these deprecated endpoints. Currently these tests are being ignored if the feature flag is true (viz. schema_endpoints_disabled = true) as part of MR (!257 (merged))
Update -- the GET /query/kinds endpoint ended up being taken out from under the feature flag and retained as it is needed for the storage concern around what kinds are actually in storage vs. merely defined in the Schema Service.