Update sdk/platform-tools to version 27.0.1

Command used to update:
  rm -rf sdk/platform-tools &&
  wget https://dl.google.com/android/repository/platform-tools-latest-linux.zip &&
  unzip platform-tools-latest-linux.zip -d sdk &&
  rm platform-tools-latest-linux.zip && git add .

Bug: 817527
Change-Id: Ic171f4ec76967aaaf1688f77ac72a8a7ce10660a
Reviewed-on: https://chromium-review.googlesource.com/943182
Reviewed-by: John Budorick <jbudorick@chromium.org>