Decouple API boundaries from packaging

This was an initial coupling oversight that wasn't caught until the go
bindings were generated/used (since python doesn't care).

This should have never been coupled in the first place since
config_bundle is a packaging detail in how we distro the payloads and
doesn't really define the API boundaries.

BUG=chromium:1062830
TEST=None

Change-Id: If43dd40b32de07912ee1a8cedc3726979aa8e740
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/config/+/2129654
Commit-Queue: C Shapiro <shapiroc@chromium.org>
Tested-by: C Shapiro <shapiroc@chromium.org>
Reviewed-by: Andrew Lamb <andrewlamb@chromium.org>
Reviewed-by: David Burger <dburger@chromium.org>
Reviewed-by: Sean McAllister <smcallis@google.com>
Auto-Submit: C Shapiro <shapiroc@chromium.org>
diff --git a/payload_utils/checker/io_utils.py b/payload_utils/checker/io_utils.py
index 35d10cd..a1f708a 100644
--- a/payload_utils/checker/io_utils.py
+++ b/payload_utils/checker/io_utils.py
@@ -5,7 +5,7 @@
 
 import os
 
-from bindings.api import config_bundle_pb2
+from bindings.payload import config_bundle_pb2
 
 
 def read_config(path: str) -> config_bundle_pb2.ConfigBundle: