ash: Add logic to notify power manager on notifications

This change adds functionality to support lock screen notifications for
Android. The notification module now notifies power manager of a user
activity in case a notification is posted or updated. This is done to
transition the device to a full resume from a dark resume in case
Android draws a notification in response to an alarm or a network
packet. This change also adss more functionality to the existing bare
bones fake message center.

BUG=chromium:898297
TEST=End to end test with Android applications.

Change-Id: Ie915c1f8a15b0bb74b2061fdcac6d6af6132ce19
Reviewed-on: https://chromium-review.googlesource.com/c/1372557
Commit-Queue: Abhishek Bhardwaj <abhishekbh@chromium.org>
Reviewed-by: Dan Erat <derat@chromium.org>
Reviewed-by: Yoshiki Iguchi <yoshiki@chromium.org>
Cr-Commit-Position: refs/heads/master@{#636373}
12 files changed