Expose some factories for aidl_test.go

Because aidl_interface depends on some ndk modules, their factories are
exposed so that aidl_test.go can use them.

Bug: n/a
Test: m
Change-Id: I98d282cc77310d5896a7abaf3936456a14d56ccf
diff --git a/cc/ndk_library.go b/cc/ndk_library.go
index da94d33..00338b9 100644
--- a/cc/ndk_library.go
+++ b/cc/ndk_library.go
@@ -228,7 +228,7 @@
 	}
 }
 
-func ndkApiMutator(mctx android.BottomUpMutatorContext) {
+func NdkApiMutator(mctx android.BottomUpMutatorContext) {
 	if m, ok := mctx.Module().(*Module); ok {
 		if m.Enabled() {
 			if compiler, ok := m.compiler.(*stubDecorator); ok {
@@ -390,7 +390,7 @@
 
 // ndk_library creates a stub library that exposes dummy implementation
 // of functions and variables for use at build time only.
-func ndkLibraryFactory() android.Module {
+func NdkLibraryFactory() android.Module {
 	module := newStubLibrary()
 	android.InitAndroidArchModule(module, android.DeviceSupported, android.MultilibBoth)
 	module.ModuleBase.EnableNativeBridgeSupportByDefault()