Fix clinit-related serialization incompatibility.

For the code:
class Parent {
  some code that will create <clinit>
}
class Child extends Parent {}

java.io.ObjectStreamClass.hasStaticInitializer(Child.class)
was returning false. This is technically valid, but historically
android was returning true in this case. This causes
problems with deserializing classes like Child without
explicit serialVersionUID. To mitigate the problem, this
change reverts to old behavior if sdk target <= 23.

Bug: 29064453
Change-Id: Iaff269ced01543469a30b50673a04d3d8722d261