Generate ABI dumps for libraries without source

This commit enables ABI diff for libraries without source.
Stub libraries are excluded.

Test: ./create_reference_dumps.py -products aosp_arm64
Test: make
Bug: 135728451
Change-Id: Idbe276db6f5e057175fc098f0226cb38996faa17
diff --git a/cc/library.go b/cc/library.go
index fab5837..4b50da4 100644
--- a/cc/library.go
+++ b/cc/library.go
@@ -810,7 +810,7 @@
 }
 
 func (library *libraryDecorator) linkSAbiDumpFiles(ctx ModuleContext, objs Objects, fileName string, soFile android.Path) {
-	if len(objs.sAbiDumpFiles) > 0 && library.shouldCreateVndkSourceAbiDump(ctx) {
+	if library.shouldCreateVndkSourceAbiDump(ctx) {
 		vndkVersion := ctx.DeviceConfig().PlatformVndkVersion()
 		if ver := ctx.DeviceConfig().VndkVersion(); ver != "" && ver != "current" {
 			vndkVersion = ver