Prevent InvalidCastException when attribute type does not match parameter type by adding safe type conversion.

[minaxi98]

Prevent InvalidCastException when attribute type does not match parameter type by adding safe type conversion.

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Summary of the changes (Less than 80 chars)

Description

The problem: when DefaultParameterValue(10) is used on a uint64 parameter, the 10 is a boxed int32, and JsonSerializer.SerializeToNode calls UnboxOnWrite which can't directly unbox an int32.

The fix: convert defaultValue to the target type before serializing:

Fixes #60019 (in this specific format)

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Thanks for your PR, @minaxi98. Someone from the team will get assigned to your PR shortly and we'll get it reviewed.