Support Turbine in Soong.

If sdk jars(android_stubs_current, etc) are compiled using soong java
modules, we have to filter them when running Java build with Turbine.

TODO: provide more unit-tests.

Test: m clean && m -j32; go test java_test

Change-Id: Iad7c241b0e8b0ca760950733f513124b56c84564
diff --git a/java/system_modules.go b/java/system_modules.go
index ddfc5cf..ce66a7c 100644
--- a/java/system_modules.go
+++ b/java/system_modules.go
@@ -115,7 +115,7 @@
 	ctx.VisitDirectDeps(func(module blueprint.Module) {
 		if ctx.OtherModuleDependencyTag(module) == libTag {
 			dep, _ := module.(Dependency)
-			jars = append(jars, dep.ClasspathFiles()...)
+			jars = append(jars, dep.HeaderJars()...)
 		}
 	})