Give resume_on_reboot key as separate context

As part of the keystore2 requirement, we give the keys used for
resume on reboot a separate context in keystore. And grant system
server the permission to generate, use and delete it.

Bug: 172780686
Test: resume on reboot works after using keystore2
Change-Id: I6b47625a0864a4aa87b815c6d2009cc19ad151a0
3 files changed