Revert "Do not cache wildcard users (PackageManager)"

This reverts commit 8d6900e0.

Reason for revert: The UIDs in this CL are Linux UIDs, which are never
negative.  The @UserIdInt annotation is incorrect and the bypass()
override is unnecessary.  See the comments on ag/15339446 for another
instance of this issue.

Change-Id: I79ccbb40c3f0ab1a3bb48f55da5a72696d4fb2b1