Allow import from S3 URL via remote-import when import_project_from_remote_file_s3 feature flag is enabled

When remote-import-s3 is enabled, users can no longer use remote-import to import pre-signed URLs from S3 because remote-import starts to block imports from S3 and recommends the user to use remote-import-s3 endpoint.

Since there are cases where users can't use AWS credentials to import directly from S3 via remote-import-s3, such as this case, we shouldn't block users from using S3 pre-signed URLs in remote-import if remote-import-s3 is enabled.

Solution

Remove import_project_from_remote_file_s3 feature flag validations from Import::GitlabProjects::FileAcquisitionStrategies::RemoteFile