Show error message when Android.mk files are found in directories in the deny list.

Bug: 318567881
Test: CIs
Test: add a Android.mk file in a blocked directory(e.g. cts/) and 'm nothing', an error message should be displayed and build process is stopped.
Change-Id: I3e1f63a13a20f77576b0e7424304a661f144df53
diff --git a/ui/build/androidmk_denylist.go b/ui/build/androidmk_denylist.go
index e004cdc..9aeaf9d 100644
--- a/ui/build/androidmk_denylist.go
+++ b/ui/build/androidmk_denylist.go
@@ -16,8 +16,6 @@
 
 import (
 	"strings"
-
-	"android/soong/android"
 )
 
 var androidmk_denylist []string = []string{
@@ -35,13 +33,13 @@
 	"toolchain/",
 }
 
-func blockAndroidMks(androidMks []string) []string {
-	return android.FilterListPred(androidMks, func(s string) bool {
+func blockAndroidMks(ctx Context, androidMks []string) {
+	for _, mkFile := range androidMks {
 		for _, d := range androidmk_denylist {
-			if strings.HasPrefix(s, d) {
-				return false
+			if strings.HasPrefix(mkFile, d) {
+				ctx.Fatalf("Found blocked Android.mk file: %s. "+
+					"Please see androidmk_denylist.go for the blocked directories and contact build system team if the file should not be blocked.", mkFile)
 			}
 		}
-		return true
-	})
+	}
 }