Temporary fix for PermissionInfo.FLAG_INSTALLED returned in PackageInfo.

The old BasePermission implementation shared the same instance of
ParsedPermission with ParsedPackage, and mutated this input by
conditionally adding FLAG_INSTALLED. This is certainly not the
greatest design but we need to keep it working for now, before we
figure out a better solution.

Fixes: 171052955
Test: manual
Change-Id: Ia2c00a3b4467820e5cb1ce0c3d4ef81566926989