IssueTracker

As mentioned in https://issuetracker.google.com/173472486, complementary operations now cancel each other out.

We should create a lint warning notifying developers that using attach() and detach() in the same transaction on the same fragment will no longer destroy and recreate the fragment's view like it used to and if they want this behavior they should separate them into two separate transactions.

This bug is only for detecting the same usage, in the future it would be nice if we had two lint rules that specifically address the differences in ordering of these methods (i.e. doing an detach() then attach() vs doing an attach() then detach()).