Save ShortcutUser before rewriting ShortcutPackageItems

This change modifies ShortcutService.injectSaveUser to save the
ShortcutUser before rewriting ShortcutPackageItems. This way, if
saveUserInternalLocked fails, we avoid deleting the ShortcutPackageItems
(because we won't be able to rewrite them).

Bug: 417712196
Test: Manually tested with repro steps from the bug
Flag: EXEMPT bugfix
Change-Id: I567b4d8efa0610da54dd96c84c038f1fde7b8cf2
1 file changed