Kernel mapping for package scope by user

Inform the kernel via configfs, of userids that
should be excluded when an app is not installed
for them.

Also push userid to remove_userid when a user is
removed so that the exclude list of that user can
be cleaned up in one command for all packages.

Test: runtest -x ....KernelPackageMappingTests.java
Change-Id: Ib94b1a0b737f45b2d03deb9650f0f0eb68e363d9