Support ASAN for ckati and ninja

I missed this when converting to soong_ui.

Test: m -j blueprint_tools (check soong.log)
Test: SANITIZE_HOST=address m -j blueprint_tools
Change-Id: I01eb567db6848dc36dd679557291a4e600a63bba
diff --git a/ui/build/kati.go b/ui/build/kati.go
index f990767..218ca69 100644
--- a/ui/build/kati.go
+++ b/ui/build/kati.go
@@ -65,7 +65,7 @@
 
 	genKatiSuffix(ctx, config)
 
-	executable := "prebuilts/build-tools/" + config.HostPrebuiltTag() + "/bin/ckati"
+	executable := config.PrebuiltBuildTool("ckati")
 	args := []string{
 		"--ninja",
 		"--ninja_dir=" + config.OutDir(),