android: switch stack.py to py3

Installing python-is-python2 is getting more and more annoying. With py3
the script worked on a trivial input.

Bug: None
Change-Id: I9e3b4008fb9bef1397b19dc1bab932e581d74843
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3540500
Reviewed-by: Andrew Grieve <agrieve@chromium.org>
Commit-Queue: Egor Pasko <pasko@chromium.org>
Cr-Commit-Position: refs/heads/main@{#983359}
NOKEYCHECK=True
GitOrigin-RevId: 566e2367dffa7126129109f20b79743b054dc4a8
diff --git a/development/scripts/stack b/development/scripts/stack
index ea0d1d7..607a898 100755
--- a/development/scripts/stack
+++ b/development/scripts/stack
@@ -1,8 +1,8 @@
-#! /bin/bash
+#!/bin/bash
 # Copyright 2017 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
-base_dir=$(dirname "$0")
+BASE_DIR=$(dirname "$0")
 
-exec python "$base_dir/stack.py" "$@"
+exec python3 "$BASE_DIR/stack.py" "$@"
diff --git a/development/scripts/stack.py b/development/scripts/stack.py
index 6e562b4..0bc8669 100755
--- a/development/scripts/stack.py
+++ b/development/scripts/stack.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 #
 # Copyright (C) 2013 The Android Open Source Project
 #