Allow any app to dynamically install a split

Any application starting an activity resolved to a dyanmic split
should initiate split installation. Previously, only the application
defining the split could start installation of the split.

Bug: 62872325
Test: Manual; install instant app and start intent using 'adb shell am' and see that dynamic split installation occurs
Change-Id: I232dc5df82fb2c04653015a4a6b9f07c9e382205