Add a backup and restore logic to ShortcutPackageItems

If shortcut package or launcher xml file is corrupted, booting would be
failed. It makes a reservecopy file when writing the files and use it
if the original file is corrupted.

Bug: 269072872
Test: atest ShortcutManagerTest1
Change-Id: I91b50db46f3eadf98e6a9eb96165be2ad3c7646a