Depend on all the files from system modules

Instead of just one of the files that we pass into javac.

Test: treehugger
Change-Id: I8478e88656487c9f667893d7c17839f0ea63c78f
diff --git a/java/sdk_test.go b/java/sdk_test.go
index 915333e..953c372 100644
--- a/java/sdk_test.go
+++ b/java/sdk_test.go
@@ -254,7 +254,7 @@
 			if testcase.system == "none" {
 				system = "--system=none"
 			} else if testcase.system != "" {
-				system = "--system=" + filepath.Join(buildDir, ".intermediates", testcase.system, "android_common", "system") + "/"
+				system = "--system=" + filepath.Join(buildDir, ".intermediates", testcase.system, "android_common", "system")
 			}
 
 			checkClasspath := func(t *testing.T, ctx *android.TestContext) {