Fix a bug disappearing installerPackageName info of packages after reboot.

If user install apps from playstore, system has installerPackageName attribute of app.
but, after reboot, some apps(have sharedUserID) installerPackageName attribute disappearing.
because lack of copy routine.
So, I added copy routine(installerPackageName).

Testcase :
1. Install app(has sharedUserId, ex Lync2013) from market.
2. Confirm package info from packages.xml(exist installer info).
3. reboot.
4. Re-confirm package info from packages.xml(not exist installer info).

Cherry-pick from AOSP master.
Bug 22513758

Change-Id: I3fea3e573c056f6c2f574715d2ebef4df8b75a68