dynamically install all missing splits

In O, we allowed Instant Apps to dynamically install missing
splits.  We removed that limit and allow any application [ie.
full applications] to dynamically install missing splits.

This functionality only works on activities. Missing splits
will not be dynamically installed when referencing other
components such as receivers, providers or services.

Change-Id: Iab1db1ebc80f517d711ae113e68d7adcc2a39d9f
Fixes: 63112542
Test: Manual.
Test: Install a app that references a split that isn't installed
Test: Invoke the missing split and see that the installer is launched