.Net: Bug: GoogleAI Gemini Api key credential should be passed using headers value?

[jliu-mycarrier]

Describe the bug
Recently I have implemented some agents using Gemini from Google AI (not Vertex AI) and then I realized that the entire URL is showing in OTEL. Once I did a little further, I realized the connector is following the suggestion from Google Official Document (https://ai.google.dev/gemini-api/docs/api-key), but shouldn't we use http header values [X-goog-api-key] instead? so we can easily redact the value in the log?

Expected behavior
You will see the entire POST URL in OTEL

Screenshots

Platform

• Language: C#

[markwallace-microsoft]

@jliu-mycarrier Would you be able to create a PR with this change?