Ensure to add Persistent Apps to LruProcess List on app restart

This change will ensure to add Persistent Apps to mLruProcesses
if not already present while restarting.Previously, on some
occasions, the process was not getting added to the list
resulting in SecurityException as this process was not found
in the mLruProcesses.

Change-Id: I26813a794e01aae316dffd3cf2bb38ab66ac69a9