Move persistent notification id from notification database to profile.

Create a profile field that has the persistent notification ID, where it
can be stored on disk, as this value needs to persist across restarts.

Updating related unit tests.

Bug: 856603
Change-Id: I5c7083c8359c5e7fd7a2b612b861e8968150e90f
Commit-Queue: Sharon Yang <>
Reviewed-by: Peter Beverloo <>
Reviewed-by: Avi Drissman <>
Cr-Commit-Position: refs/heads/master@{#575236}
19 files changed