Merge changes from topic "index_instead_of_offset" into main

* changes:
  aconfig: update storage write api
  aconfig: update storage read api
  aconfig: update storage file creation to allow storage files to store flag index instead of byte offset
  aconfig: update storage file to store flag index instead of file byte offset
diff --git a/tools/releasetools/ota_from_target_files.py b/tools/releasetools/ota_from_target_files.py
index 67438e6..2c5fe0d 100755
--- a/tools/releasetools/ota_from_target_files.py
+++ b/tools/releasetools/ota_from_target_files.py
@@ -1288,7 +1288,7 @@
       assert len(words) >= 1 and len(words) <= 2
       OPTIONS.vabc_compression_param = a.lower()
       if len(words) == 2:
-        if not words[1].isdigit():
+        if not words[1].lstrip("-").isdigit():
           raise ValueError("Cannot parse value %r for option $COMPRESSION_LEVEL - only "
                            "integers are allowed." % words[1])
     elif o == "--security_patch_level":