.Net: Bug: Google AI client ignores modelId passed to PromptExecutionSettings

[dszymon]

Describe the bug
Google AI client always uses modelId passed to the constructor

To Reproduce
Steps to reproduce the behavior:

1. Create an instance of Google AI client
2. Pass model1 to the constructor
3. Use a different model in PromptExecutionSettings passed to any generation method
4. Client ignores the ModelId property

Expected behavior
Client should always prefer ModelId from PromptExecutionSettings

Platform

• Language: C#
• Source: Microsoft.SemanticKernel.Connectors.Google 1.66.0-alpha (nuget)
• AI model: any
• IDE: Rider
• OS: any