Fix package usage of instant app can be updated by unprivileged app

IPackageManager#notifyPackageUse used #isInstantApp api to determine
whether the target package is instant app or not. But #isInstantApp
return true only if called by itself or by somebody who can view
instant apps or by somebody has has been granted with access. It
results in the api fails to check instant app then allowing an
unprivileged app to update the package usage of an instant app.

This CL uses #isInstantAppInternal with the system uid to pass the
checks and fix the issue.

Bug: 201534884
Test: Manual, follow the steps in the bug
Change-Id: I4ad68be5145a165e8d8c93b6d26ccf0e8bc084c3