Move 'un/install' to cmd

Move the implementation of the install variants and uninstall to the cmd
command. Additionally, make two other important changes: 1) replace calls
to the legacy PackageManager#installPackageAsUser with the PackageInstaller
2) allow streaming package bits for 'pm install'

Change-Id: I5680f57208d377daadb69b2cc09c233c02fe5016
3 files changed