Fix bugs around restoring nested retained instance fragments

Framework edition

In a few configurations the child fragment state of a
retained-instance fragment would not be preserved correctly, leading
to child fragments not being restored. Clean this up along with live
state management issues that were leading to logged warnings during
normal fragment operation.

Bug 27371492
Bug 27477824

Change-Id: I847ac05b1757392580e008dc20c50c3ef365ca68