Converter tests:

Change test data files extension to "java"

j2k/tests/testData/ast/issues/kt-696.java

@@ -0,0 +1,36 @@
+//file
+package test;
+
+class Base {
+  @Override
+  public int hashCode() {
+    return super.hashCode();
+  }
+
+  @Override
+  public boolean equals(Object o) {
+    return super.equals(o);
+  }
+
+  @Override
+  public String toString() {
+    return super.toString();
+  }
+}
+
+class Child extends Base {
+  @Override
+  public int hashCode() {
+    return super.hashCode();
+  }
+
+  @Override
+  public boolean equals(Object o) {
+    return super.equals(o);
+  }
+
+  @Override
+  public String toString() {
+    return super.toString();
+  }
+}