[3xH] Use gclient wrapper script to invoke gclient correctly

gclient now needs to be run with vpython3. Using the wrapper script will
always give us the right wrapper. Running gclient.py directly means that
python3 would be invoked and gclient's dependencies are assumed to be
installed already.

Fixes: #48486
Change-Id: Id62507965ac4f2d18e26dbc7907fcbc563af8e98
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/234721
Reviewed-by: William Hesse <whesse@google.com>

tools/patches/flutter-engine/apply.sh

@@ -62,7 +62,7 @@ if [ $need_runhooks = true ]; then
   # DEPS file might have been patched with new version of packages that
   # Dart SDK depends on. Get information about dependencies from the
   # DEPS file and forcefully update checkouts of those dependencies.
-  gclient.py revinfo --ignore-dep-type=cipd | grep 'src/third_party/dart/third_party' | while read -r line; do
+  gclient revinfo --ignore-dep-type=cipd | grep 'src/third_party/dart/third_party' | while read -r line; do
     # revinfo would produce lines in the following format:
     #     path: git-url@tag-or-hash
     # Where no spaces occur inside path, git-url or tag-or-hash.
@@ -97,5 +97,5 @@ if [ $need_runhooks = true ]; then
     fi
     popd > /dev/null
   done
-  gclient.py runhooks
+  gclient runhooks
 fi