Add @UnderMigration annotation and options for report level

compiler/testData/foreignAnnotations/testAnnotations/MyMigrationNullable.java

@@ -0,0 +1,18 @@
+import javax.annotation.*;
+import java.lang.annotation.Documented;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+
+import javax.annotation.meta.TypeQualifierNickname;
+import javax.annotation.meta.When;
+
+import kotlin.annotations.jvm.*;
+
+@Documented
+@TypeQualifierNickname
+@Nonnull(when = When.MAYBE)
+@Retention(RetentionPolicy.RUNTIME)
+@UnderMigration(status = MigrationStatus.WARN)
+public @interface MyMigrationNullable {
+
+}