Inline cc.TestFactory() and un-export it.

This allows art_cc_test factory to disable bp2build/bazelable.

Test: presubmits
Change-Id: I93245eb9949bcfc395be7cfcee22fe76c5d3ac77
diff --git a/build/art.go b/build/art.go
index 672f282..383517b 100644
--- a/build/art.go
+++ b/build/art.go
@@ -463,7 +463,8 @@
 }
 
 func artTest() android.Module {
-	module := cc.TestFactory()
+	// Disable bp2build.
+	module := cc.NewTest(android.HostAndDeviceSupported, false /* bazelable */).Init()
 
 	installCodegenCustomizer(module, binary)