[build] Activate assert to check GN SDK version is equal to manifest

Bug: 891996
Change-Id: I5904066ca893c536cbed87b3e6fa55b1210f5f65
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1675323
Auto-Submit: Tibor Goldschwendt <tiborg@chromium.org>
Commit-Queue: Eric Stevenson <estevenson@chromium.org>
Reviewed-by: Eric Stevenson <estevenson@chromium.org>
Cr-Commit-Position: refs/heads/master@{#672090}

build/android/gyp/util/manifest_utils.py

@@ -74,11 +74,6 @@ def AssertUsesSdk(manifest_node,
   Will only assert if both the passed value is not None and the value of
   attribute exist.
   """
-  # TODO(crbug.com/891996): Activate once all dependency repos have been
-  # updated.
-  # pylint: disable=unreachable
-  return
-
   uses_sdk_node = manifest_node.find('./uses-sdk')
   if uses_sdk_node is None:
     return