De-obfuscate tofa/VertexAI code

ee/lib/api/ai/experimentation/vertex_ai.rb

ee/lib/ee/api/api.rb

...b/gitlab/llm/open_ai/completions/explain_vulnerability.rb

ee/lib/gitlab/llm/vertex_ai/client.rb

...gitlab/llm/vertex_ai/completions/explain_vulnerability.rb

ee/lib/gitlab/llm/vertex_ai/configuration.rb

ee/spec/lib/gitlab/llm/concerns/exponential_backoff_spec.rb

...itlab/llm/open_ai/templates/explain_vulnerability_spec.rb

ee/spec/lib/gitlab/llm/vertex_ai/client_spec.rb

...b/llm/vertex_ai/completions/explain_vulnerability_spec.rb

ee/spec/lib/gitlab/llm/vertex_ai/configuration_spec.rb

ee/spec/requests/api/ai/experimentation/vertex_ai_spec.rb