Make hiddenapi use prebuilt stubs when it should

Bug: 160455085
Test: build_unbundled_mainline_module.sh (with disabled source-stubs)
Test: hiddenapi_singleton_test.go
Change-Id: Id93c974351b3f8efdf8e4efe4192d3809f4fcaa5
diff --git a/java/testing.go b/java/testing.go
index 322dc9e..a472413 100644
--- a/java/testing.go
+++ b/java/testing.go
@@ -88,7 +88,7 @@
 		"prebuilts/sdk/30/system/api/bar-removed.txt":              nil,
 		"prebuilts/sdk/30/test/api/bar-removed.txt":                nil,
 		"prebuilts/sdk/tools/core-lambda-stubs.jar":                nil,
-		"prebuilts/sdk/Android.bp":                                 []byte(`prebuilt_apis { name: "sdk", api_dirs: ["14", "28", "30", "current"],}`),
+		"prebuilts/sdk/Android.bp":                                 []byte(`prebuilt_apis { name: "sdk", api_dirs: ["14", "28", "30", "current"], imports_sdk_version: "none", imports_compile_dex:true,}`),
 
 		"bin.py": nil,
 		python.StubTemplateHost: []byte(`PYTHON_BINARY = '%interpreter%'