Updating stale merge_manifest.py comment

Change-Id: I4ce96aa73a4377be2deb08060564f2ff7718d976
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2025924
Commit-Queue: Sam Maier <smaier@chromium.org>
Commit-Queue: Andrew Grieve <agrieve@chromium.org>
Reviewed-by: Andrew Grieve <agrieve@chromium.org>
Auto-Submit: Sam Maier <smaier@chromium.org>
Cr-Commit-Position: refs/heads/master@{#736384}

build/android/gyp/merge_manifest.py

@@ -31,10 +31,8 @@ _MANIFEST_MERGER_JARS = [
 @contextlib.contextmanager
 def _ProcessManifest(manifest_path, min_sdk_version, target_sdk_version,
                      max_sdk_version, manifest_package):
-  """Patches an Android manifest to always include the 'tools' namespace
-  declaration, as it is not propagated by the manifest merger from the SDK.
-
-  See https://issuetracker.google.com/issues/63411481
+  """Patches an Android manifest's package and performs assertions to ensure
+  correctness for the manifest.
   """
   doc, manifest, _ = manifest_utils.ParseManifest(manifest_path)
   manifest_utils.AssertUsesSdk(manifest, min_sdk_version, target_sdk_version,