Workaround the fake-package symlink issue faced on Q

* For some reason, the fake packages generating the standalone
  symlinks were never called. They're present in PRODUCT_PACKAGES
  yet building any of the normal targets
  (m or m vendorimage or m $OUT/vendor.img)
  did not build them. Building them manually worked, and so did
  (mmm vendor/google_devices/$device)
* Switch to REQUIRED_MODULES instead, as that does work.
* We copy the file_signatures.txt file right now, but it can be any
  other file too.

Signed-off-by: spezi77 <[email protected]>

scripts/generate-vendor.sh

@@ -587,12 +587,26 @@ gen_standalone_symlinks() {
 
   if [ ! -z "${pkgs_SSLinks-}" ]; then
     {
-      echo "# Standalone symbolic links"
-      echo 'PRODUCT_PACKAGES += \'
+      echo -e "\ninclude \$(CLEAR_VARS)"
+      echo 'LOCAL_MODULE := apv_file_signatures'
+      echo 'LOCAL_MODULE_CLASS := ETC'
+      echo 'LOCAL_MODULE_TAGS := optional'
+      echo -e "LOCAL_MODULE_OWNER := $VENDOR"
+      echo 'LOCAL_MODULE_PATH := $(TARGET_OUT_VENDOR_ETC)'
+      echo 'LOCAL_MODULE_STEM := file_signatures.txt'
+      echo 'LOCAL_SRC_FILES := file_signatures.txt'
+      echo 'LOCAL_REQUIRED_MODULES := \'
       for module in "${pkgs_SSLinks[@]}"
       do
         echo "    $module \\"
       done
+    } >> "$ANDROID_MK"
+    strip_trail_slash_from_file "$ANDROID_MK"
+    echo 'include $(BUILD_PREBUILT)' >> "$ANDROID_MK"
+    {
+      echo "# Standalone symbolic links"
+      echo 'PRODUCT_PACKAGES += \'
+      echo -e "    apv_file_signatures\n"
     } >> "$DEVICE_VENDOR_MK"
   fi
   strip_trail_slash_from_file "$DEVICE_VENDOR_MK"