Load contavariantly projected collections in Java as mutable

#KT-3068 Fixed

compiler/testData/loadJava/compiledJava/kotlinSignature/MethodWithMappedClasses.java

@@ -6,4 +6,8 @@ public class MethodWithMappedClasses {
     public <T> void copy(List<? super T> dest, List<T> src) {
         throw new UnsupportedOperationException();
     }
+
+    public <T> void copyMap(Map<String, ? super T> dest, Map<String, T> src) {
+        throw new UnsupportedOperationException();
+    }
 }