Process the incoming intent to this app

This change will simply accept the incoming intent, extract some data from it like the action and whether its a session based install (i.e using the PackageManager APIs). Permission checks and visibility checks would be
added in subsequent changes.

Bug: 182205982
Test: builds successfully
Test: No CTS Tests. Flag to use new app is turned off by default

Change-Id: Ib60593dd0ddc283915c5877a19ec290dbe697839