Detect and recover from relative z loops

The caller can create loops in the hierarchy by relatively
reparenting layers to each other. This can be done directly
or via a chain of layers.

The logic to detect and fix this was not being called. Fix this
by making loop detection a bit harder to ignore and part of
hierarchy builder's update call.

Test: presubmit
Bug: 316236833
Change-Id: I484f9b8e2742fef22a5d76362a715eb6850c26f6