Process source_file through GetTargetFilesZipForCustomImagesUpdates

This is necessary when generating incremental OTA payloads.

Bug: 356537269
Bug: 382184433
Change-Id: Ic3850fae4f65edecd334da38f2de0c37e9aa9a51
diff --git a/tools/releasetools/ota_from_target_files.py b/tools/releasetools/ota_from_target_files.py
index 6446e1f..1a6ee29 100755
--- a/tools/releasetools/ota_from_target_files.py
+++ b/tools/releasetools/ota_from_target_files.py
@@ -1039,6 +1039,9 @@
 
   # Prepare custom images.
   if OPTIONS.custom_images:
+    if source_file is not None:
+      source_file = GetTargetFilesZipForCustomImagesUpdates(
+           source_file, OPTIONS.custom_images)
     target_file = GetTargetFilesZipForCustomImagesUpdates(
         target_file, OPTIONS.custom_images)