ignore IllegalArgumentException during uninstall

It's expected and normal to throw an IllegalArgumentException when
trying to uninstall a package that doesn't exist. Ignore it if it
gets thrown.

Bug: 38197362
Test: bit FrameworksCoreTests:android.content.pm.PackageManagerTests#testFlagFManifestI
Change-Id: Ie0d90010678b09c91747f6e5c4655691951ad3a9