Fix TestClasspath to work without javaMockFS()

Bug: 182638834
Test: m nothing
Change-Id: Icd6fe93cbda418cb4eaf5e99800894d4c4cc5e6f
diff --git a/java/sdk_test.go b/java/sdk_test.go
index 50755cf..37875a4 100644
--- a/java/sdk_test.go
+++ b/java/sdk_test.go
@@ -353,6 +353,11 @@
 			}
 
 			fixtureFactory := javaFixtureFactory.Extend(
+				FixtureWithPrebuiltApis(map[string][]string{
+					"29":      {},
+					"30":      {},
+					"current": {},
+				}),
 				android.FixtureModifyProductVariables(func(variables android.FixtureProductVariables) {
 					if testcase.unbundled {
 						variables.Unbundled_build = proptools.BoolPtr(true)