Merge "bootstat: Differentiate system update boot times." into nyc-dev
am: c264813

* commit 'c2648132d2dc5874bb49de4efdf1d9a2e12eb6e8':
  bootstat: Differentiate system update boot times.

Change-Id: I67a70f0af9198a9e0c4e712f65d5d21ad5c36df8