Resume-on-Reboot: add storage for armed status

In order to avoid marking a manual reboot as a RoR failure, add another
indicator that the resume-on-reboot was armed before the last reboot.

(cherry picked from commit 5e6a9596)

Test: atest RebootEscrowManagerTests
Bug: 149833390
Change-Id: Ief1cac1952302e43a2c57314bc1449fa7bf38ba7
Merged-In: Ief1cac1952302e43a2c57314bc1449fa7bf38ba7