fix(models): Handle empty message in LiteLLM response (fixes #3618)#3699

sarojrout wants to merge 4 commits intogoogle:maingoogle/adk-python:mainfrom

sarojrout:fix/litellm-no-message-error-3618sarojrout/adk-python:fix/litellm-no-message-error-3618Copy head branch name to clipboard