Fix autostop.py's execution state bug

[fakalyoncu]

Issue #, if available:
We've observed that sometimes notebooks/consoles getting stuck in 'starting' state.

Description of changes:
Passing only when execution state is busy will make this code work properly.

Testing Done

• Notebook Instance created successfully with the Lifecycle Configuration
• Notebook Instance stopped and started successfully
• Documentation in the script around any network access requirements
• Documentation in the script around any IAM permission requirements
• CLI commands used to validate functionality on the instance
• New script link and description added to README.md

# Provide your commands here
/you/commands/here

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