Ensure that systemserverclasspath_fragment does not depend on prebuilts

Bug: 190037398
Test: m nothing
Change-Id: I85671613c70bbfe8adde1d24d7f59ed7b53a8120
diff --git a/java/systemserver_classpath_fragment.go b/java/systemserver_classpath_fragment.go
index 7ffb056..992ade5 100644
--- a/java/systemserver_classpath_fragment.go
+++ b/java/systemserver_classpath_fragment.go
@@ -119,6 +119,11 @@
 	blueprint.BaseDependencyTag
 }
 
+// The systemserverclasspath_fragment contents must never depend on prebuilts.
+func (systemServerClasspathFragmentContentDependencyTag) ReplaceSourceWithPrebuilt() bool {
+	return false
+}
+
 // Contents of system server fragments in an apex are considered to be directly in the apex, as if
 // they were listed in java_libs.
 func (systemServerClasspathFragmentContentDependencyTag) CopyDirectlyInAnyApex() {}