versioning macro is exported from prebuilt stubs as well

This change fixes a bug that the versioning macro (__LIBNAME_API__) is
omitted for prebuilts providing a stub.

Bug: 175166063
Test: m nothing

Change-Id: I1cce5ab58ef245622861200ec0d8b0f84e3178ed

cc/prebuilt.go

@@ -17,6 +17,7 @@ package cc
 import (
 	"android/soong/android"
 	"path/filepath"
+	"strings"
 )
 
 func init() {
@@ -117,6 +118,8 @@ func (p *prebuiltLibraryLinker) link(ctx ModuleContext,
 			return nil
 		}
 
+		p.libraryDecorator.exportVersioningMacroIfNeeded(ctx)
+
 		in := android.PathForModuleSrc(ctx, srcs[0])
 
 		if p.static() {
@@ -220,6 +223,11 @@ func (p *prebuiltLibraryLinker) disablePrebuilt() {
 	p.properties.Srcs = nil
 }
 
+// Implements versionedInterface
+func (p *prebuiltLibraryLinker) implementationModuleName(name string) string {
+	return strings.TrimPrefix(name, "prebuilt_")
+}
+
 func NewPrebuiltLibrary(hod android.HostOrDeviceSupported) (*Module, *libraryDecorator) {
 	module, library := NewLibrary(hod)
 	module.compiler = nil