Java test code clean-up

Remove unused parameters and make testJava return the config.

Test: Ran all java tests.
Change-Id: Iaa123f3fd93188e2f55452b887e1d340429cc710
diff --git a/java/dexpreopt_bootjars_test.go b/java/dexpreopt_bootjars_test.go
index f91ff69..4c38399 100644
--- a/java/dexpreopt_bootjars_test.go
+++ b/java/dexpreopt_bootjars_test.go
@@ -51,7 +51,7 @@
 	dexpreoptConfig.RuntimeApexJars = []string{"foo", "bar", "baz"}
 	setDexpreoptTestGlobalConfig(config, dexpreoptConfig)
 
-	ctx := testContext(config, bp, nil)
+	ctx := testContext(bp, nil)
 
 	ctx.RegisterSingletonType("dex_bootjars", android.SingletonFactoryAdaptor(dexpreoptBootJarsFactory))