Fix incorrect assertion examples in DynamoDbIgnoreNulls Javadoc#6826

alextwoods merged 2 commits intoaws:masteraws/aws-sdk-java-v2:masterfrom

CheHyeonYeong:fix/dynamodb-ignore-nulls-javadocCheHyeonYeong/aws-sdk-java-v2:fix/dynamodb-ignore-nulls-javadocCopy head branch name to clipboard