BulkFixProcessorTest should have FixKind

[FMorschel]

While working for #60184 at https://dart-review.googlesource.com/c/sdk/+/411101, I had to remove a behaviour from ReplaceWithVar (pkg\analysis_server\lib\src\services\correction\dart\replace_with_var.dart) that was for it to stop solving for const and final declarations and add RemoveTypeAnnotation (pkg\analysis_server\lib\src\services\correction\dart\remove_type_annotation.dart) to the list of possible fixes wherever it was so it could solve for those cases.

The problem was that while copying and pasting some of the tests for the Replace with var lint over to Remove Type Annotation, I accidentally pasted some code over OmitObviousLocalVariableTypesLintBulkTest.test_singleFile (pkg\analysis_server\test\src\services\correction\fix\replace_with_var_test.dart) adding const and final to de declarations of variables in that test.

And fortunatelly I found that when reviewing the changes but that test was passing because now the other fix was resolving that case. So I'm opening this issue to track this.

I'm not sure if there will be any case where this FixKind being added could make the tests stop passing (unless we found more cases like this) but I don't think there will be.

WDYT @bwilkerson @scheglov? Not sure how big this change would be too.