[SPARK-43976] Handle the case where modifiedConfigs doesn't exist in event logs

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 3.3.2, 3.4.0
• Fix Version/s: 3.3.3, 3.4.1, 3.5.0
• Component/s: Spark Core
• Assignee: Dongjoon Hyun
• Reporter: Dongjoon Hyun
• Created: 06/Jun/23 03:08
• Updated: 06/Jun/23 16:35
• Resolved: 06/Jun/23 16:35