[BUG] cannot use gemini or vertexai

[nayutah]

Describe the bug
The vertex ai or gemini ai is not properly set, the valid ways are:

async def make_aysnc_call1():
    os.environ["GEMINI_API_KEY"] = "xxxxx"

    response = await acompletion(
        model="gemini/gemini-2.5-pro",
        messages=[{"role": "user", "content": "write code for saying hi from LiteLLM"}]
    )
    print(response)
asyncio.run(make_aysnc_call1())

async def make_async_call2():
    file_path = '/Users/slc/Downloads/gen-lang-client-xxx.json'

    # Load the JSON file
    with open(file_path, 'r') as file:
        vertex_credentials = json.load(file)

    # Convert to JSON string
    vertex_credentials_json = json.dumps(vertex_credentials)

    ## COMPLETION CALL
    response = await acompletion(
        model="vertex_ai/gemini-2.5-pro",
        messages=[{ "content": "Hello, how are you?","role": "user"}],
        vertex_credentials=vertex_credentials_json
    )
    print(response)
asyncio.run(make_async_call2())

To Reproduce
Steps to reproduce the behavior:
1, enable google gemini ai
2, enter a valid your api_key
3, set api base with "https://generativelanguage.googleapis.com/v1beta/models/gemini-2.5-pro"
4, set llm with 'gemini/gemini-2.5-pro' in workflow
5, start a chat and ask a question
6, got errors and exceptions

Expected behavior
A clear and concise description of what you expected to happen.

Screenshots
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Desktop (please complete the following information):

• OS: [e.g. iOS]
• Browser [e.g. chrome, safari]
• Version [e.g. 22]

Additional context
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[github-actions]

This issue has been marked as stale because it has been open for 30 days with no activity