Update assignment in language/nnbd/operator_type_test
Update assignment in language/nnbd/operator_type_test

Change-Id: I81b87af6bd8ae51d626afb79412730c4bc39204a
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/138980
Reviewed-by: Erik Ernst <251bb01623bfda2cd9151e339a6e783ca432874c@google.com>
Commit-Queue: Konstantin Shcheglov <09e4d7516628963212bf4aace2f97603d2b706e4@google.com>

dart-lang/sdk,dart-lang/sdk,dart-lang/sdk,dart-lang/sdk,dart-lang/sdk,dart-lang/sdk,dart-lang/sdk,dart-lang/sdk