fix: observation toContent input param error

[hikariwo]

📝 Description

Brief description of the changes in this PR.

🔄 Type of Change

Please check the applicable options:

• [√] 🐛 Bug fix (non-breaking change which fixes an issue)
• ✨ New feature (non-breaking change which adds functionality)
• 💥 Breaking change (fix or feature that would cause existing functionality to not work as expected)
• 🔧 Refactoring (code change that neither fixes a bug nor adds a feature)
• 📚 Documentation update
• 🧪 Test improvement
• 🚀 Performance improvement
• 🎨 Style/UI change

🧪 Testing

• Unit tests added/updated
• Integration tests added/updated
• [√] Manual testing completed
• All existing tests pass

📋 Checklist

• [√] My code follows the project's style guidelines
• [√] I have performed a self-review of my own code
• [√] I have commented my code, particularly in hard-to-understand areas
• [√] I have made corresponding changes to the documentation
• [√] My changes generate no new warnings

🔗 Related Issues

Closes #(issue number)

📸 Screenshots (if applicable)

Add screenshots here if UI changes are involved.

📋 Additional Notes

observation.toContent method accepts a parameter "isMultimodalSupported" for adding the tool attachment to the output. But here, the wrong parameter is provided.

[hikariwo]

cc. @willishz @Aozh @xiaoailiang

[willishz]

+1