[pm] fix PackageInfo.signatures for archived apps

The deprecated field is still widely used. Make sure to assign correct
value to it for archived or delete_keep_data apps.

BUG: 309841702
Test: atest
android.content.pm.cts.PackageManagerTest#testUninstallWithKeepData

Change-Id: I177a45f936adaf0597399d66ab1e3f3eb7f8594c
3 files changed