Intercept direct launch of instant app installer

The instant app installer is not designed to be launched directly
by 3p apps. Instead, intercept the launch and make it look like
a "normal" instant app launch.

Bug: 33073524
Test: Built and notice poorly behaving apps [*cough* keep *cough*] now launch instant apps
Change-Id: I89c9b8c56865e260a2b92f8c2312a305a74f9cf5