Fix #2985 by using proper types.

[wmdietl]

No description provided.

[smillst]

The misc failure is:

Task :framework:runErrorProne
/__w/1/s/framework/src/main/java/org/checkerframework/framework/util/ContractsUtils.java:132: warning: [UnusedVariable] The parameter 'clazz' is never read.
            Contract.Kind kind, AnnotationMirror contractAnnotation, Class<T> clazz) {
                                                                              ^
    (see https://errorprone.info/bugpattern/UnusedVariable)
  Did you mean 'Contract.Kind kind, AnnotationMirror contractAnnotation) {'?
error: warnings found and -Werror specified
1 error
1 warning

[wmdietl]

I've suppressed the warning. The parameter is needed to determine the return type.

[smillst]

Instead of suppressing this warning and the ErrorProne warning, you could use clazz.cast(...) instead. Any reason not to do that?

[wmdietl]

No reason, clazz.cast is indeed much nicer.