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: Ia49dac0ccd6470f9d1c1964bdeb3c0b22b856075
3 files changed