Mark persistent apps as such when the ProcessRecord is created

...rather than only during the OS's "time to start the persistent apps"
boot phase.  This closes a window of opportunity during which a
persistent app container may be live without having been properly
noted as such, because it wound up being launched prior to the
[rather late] boot phase at which the persistent apps are directly
enumerated and bookkeeping for them established.

Bug 20855725

Change-Id: I41822b412de4540dbdeab300b38089303678f76c