Fix NullReferenceException with structured logging

[normj]

Issue #, if available:
#2121

Description of changes:
Amazon.Lambda.RuntimeSupport was lacking null protection if the message template was null and structured logging was enabled.

In addition Amazon.Lambda.Logging.AspNetCore was logging for the message template by looking at the log state for the key {OriginalFormat}. There are scenarios where there will be no {OriginalFormat} key. For example enabling HttpLogging. I updated Amazon.Lambda.Logging.AspNetCore to detect if there was no message template and if there was not one found use the passed in formatter using the state and exception to get a message template.

A later enhancement we should do is extend the RuntimeSupport logging API to pass in the other parameters from the message state that are now not going to be in the formatted message template and get them still included in the structured logging. That is a bigger scope then this null fix.

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.

[Copilot]

Pull Request Overview

This PR fixes NullReferenceException issues in AWS Lambda logging when message templates are null and structured logging is enabled. The fix adds null protection across multiple logging components and includes a fallback mechanism for scenarios where no message template is available.

• Added null checks and fallback to empty string for message templates in RuntimeSupport
• Enhanced AspNetCore logging to use formatter when OriginalFormat key is missing
• Added comprehensive test coverage for null message template scenarios

Reviewed Changes

Copilot reviewed 7 out of 7 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
JsonLogMessageFormatter.cs	Added null coalescing operators to prevent NullReferenceException when MessageTemplate is null
ConsoleLoggerWriter.cs	Added null protection for messageTemplate parameter
LambdaILogger.cs	Added fallback to use formatter when messageTemplate is null
LogMessageFormatterTests.cs	Added test cases for null message template scenarios
LoggingTests.cs	Added test for logging without OriginalFormat key and fixed null exception handling
84836f7b-8e69-44a1-87dc-22971f426990.json	Version bump configuration for both affected packages

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