Remove obsolete llndk_library

Remove llndk_library in favor of cc_library with llndk.symbol_file.

Bug: 170784825
Test: m checkbuild
Test: TestLlndkLibrary
Change-Id: I43580976589a7a2a176d7442be53fa043c0c8324

cc/image.go

@@ -437,15 +437,11 @@ func MutateImage(mctx android.BaseModuleContext, m ImageMutatableModule) {
 		productVndkVersion = platformVndkVersion
 	}
 
-	if m.IsLlndkLibrary() || m.NeedsLlndkVariants() {
+	if m.NeedsLlndkVariants() {
 		// This is an LLNDK library.  The implementation of the library will be on /system,
 		// and vendor and product variants will be created with LLNDK stubs.
 		// The LLNDK libraries need vendor variants even if there is no VNDK.
-		// The obsolete llndk_library and llndk_headers modules also need the vendor variants
-		// so the cc_library LLNDK stubs can depend on them.
-		if m.NeedsLlndkVariants() {
-			coreVariantNeeded = true
-		}
+		coreVariantNeeded = true
 		if platformVndkVersion != "" {
 			vendorVariants = append(vendorVariants, platformVndkVersion)
 			productVariants = append(productVariants, platformVndkVersion)