Include package name in tron events.

Add this state to Runtime, together with a getter and setter to it can be
passed at zygote fork time.

The package name needs to be included in the event itself, as the PID/UID
also present are not used to look up the package name later.

Bug: 77517571
Test: m
Test: $ adb lolcat -b events | grep sysui_multi_action
Change-Id: I40ec89152b5ecc9a81555f2e74bc4f4b44b2bcac