Add a snapshot of flutter/engine/src/build to our sdk

build/android/adb_gdb_chrome_public

Index: build/android/adb_gdb_chrome_public
diff --git a/build/android/adb_gdb_chrome_public b/build/android/adb_gdb_chrome_public
new file mode 100755
index 0000000000000000000000000000000000000000..4366c838e78e9f3e007c8c2650e0ab81b455fbdc
--- /dev/null
+++ b/build/android/adb_gdb_chrome_public
@@ -0,0 +1,16 @@
+#!/bin/bash
+#
+# Copyright 2015 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.
+#
+# Attach to or start a ChromePublic process and debug it.
+# See --help for details.
+#
+PROGDIR=$(dirname "$0")
+export ADB_GDB_PROGNAME=$(basename "$0")
+export ADB_GDB_ACTIVITY=com.google.android.apps.chrome.Main
+"$PROGDIR"/adb_gdb \
+    --program-name=ChromePublic \
+    --package-name=org.chromium.chrome \
+    "$@"