Moved javaAgainstKotlin cases to generated test.

compiler/testData/loadJava/javaAgainstKotlin/signaturePropagation/SubclassingKotlinInJava/JavaSubclass.java

@@ -0,0 +1,7 @@
+package test;
+
+public class JavaSubclass extends KotlinClass {
+    public String foo() {
+        return "";
+    }
+}

compiler/testData/loadJava/javaAgainstKotlin/signaturePropagation/SubclassingKotlinInJava/KotlinClass.kt

@@ -0,0 +1,5 @@
+package test
+
+public open class KotlinClass {
+    public open fun foo(): String = ""
+}