Fix issue with apps restored to lower versions.

When restoring to a new device, if a restored app is not compatible
with the old version (e.g. lower version or different signature),
then we won't restore shortcuts, which is working as expected.

However when it happens, the shortcut manager forgot to "un-shadow"
the package information, causing the app to not have shortcuts at all.

Test: adb shell am instrument -e class com.android.server.pm.ShortcutManagerTest1 -w com.android.frameworks.servicestests

Bug 32999759

Change-Id: I89832360114de0ce1c57d763bcaccab4fdb87b6d