Revert "bump google-generativeai to 0.4 (#12085)" (#12126)

...s/embeddings/llama-index-embeddings-gemini/pyproject.toml

...s/embeddings/llama-index-embeddings-google/pyproject.toml

...-integrations/llms/llama-index-llms-gemini/pyproject.toml

...ex-integrations/llms/llama-index-llms-palm/pyproject.toml

...l_llms/llama-index-multi-modal-llms-gemini/pyproject.toml

...or_stores/llama-index-vector-stores-google/pyproject.toml