Some clarifications in preparation to automatically order linker dependencies

Test: Browse the code and determine whether it's easier to understand
Bug: 66260943
Change-Id: Ia3fdb8f38e83ad8225a72c8de2804db23a90ef9b
diff --git a/cc/library.go b/cc/library.go
index f1681db..60525a1 100644
--- a/cc/library.go
+++ b/cc/library.go
@@ -155,7 +155,7 @@
 }
 
 func (f *flagExporter) exportedIncludes(ctx ModuleContext) android.Paths {
-	if ctx.vndk() && f.Properties.Target.Vendor.Export_include_dirs != nil {
+	if ctx.useVndk() && f.Properties.Target.Vendor.Export_include_dirs != nil {
 		return android.PathsForModuleSrc(ctx, f.Properties.Target.Vendor.Export_include_dirs)
 	} else {
 		return android.PathsForModuleSrc(ctx, f.Properties.Export_include_dirs)
@@ -697,7 +697,7 @@
 func (library *libraryDecorator) install(ctx ModuleContext, file android.Path) {
 	if library.shared() {
 		if ctx.Device() {
-			if ctx.vndk() {
+			if ctx.useVndk() {
 				if ctx.isVndkSp() {
 					library.baseInstaller.subDir = "vndk-sp"
 				} else if ctx.isVndk() {