Add support for launching a shortcut in WindowContainerTransaction

Some shell actions require the ability to launch a shortcut either
in a transaction and/or with other window operations (eg. Bubbles
and Split-screen).

This required changes to LauncherAppsService to support forwarding
the caller information internally from systemserver.

Bug: 209073176
Test: existing LauncherAppsService tests still pass
Change-Id: I11893abca24cab0b899c3385af0ca46932bcc9e3