installer: put toolkit version into toolkit installer lsm file

This change make users able to get the content of TOOLKIT_VERSION by
running `./install_factory_toolkit.run --lsm`, which is much faster and
easier than decompressing the whole archive.

BUG=chromium:711615
TEST=1. make toolkit BOARD=xxx
     2. cd /path/to/factory/build/
     3. ./install_factory_toolkit.run --lsm
     4. ./install_factory_toolkit.run --noexec --target z
     5. ./install_factory_toolkit.run -- --repack z \
                                         --pack-into a.run
     6. ./a.run --lsm

Change-Id: I293f2ce470d6d8b2bc923bfcb5e8dd32dce320db
Reviewed-on: https://chromium-review.googlesource.com/501667
Commit-Ready: Youcheng Syu <youcheng@google.com>
Tested-by: Youcheng Syu <youcheng@google.com>
Reviewed-by: Hung-Te Lin <hungte@chromium.org>
Reviewed-by: Pi-Hsun Shih <pihsun@chromium.org>
diff --git a/py/toolkit/installer.py b/py/toolkit/installer.py
index 01ee4e3..1fbfa36 100755
--- a/py/toolkit/installer.py
+++ b/py/toolkit/installer.py
@@ -368,7 +368,8 @@
     version_path = os.path.join(tmp_dir, VERSION_PATH)
     os.makedirs(os.path.dirname(version_path))
     file_utils.WriteFile(version_path, complete_version)
-    Spawn([cmd[0], '--append', tmp_dir, output_path], check_call=True, log=True)
+    Spawn([cmd[0], '--lsm', version_path, '--append', tmp_dir, output_path],
+          check_call=True, log=True)
   print ('\n'
          '  Factory toolkit generated at %s.\n'
          '\n'