Unfold refactor

1. Use Optional instead of Lazy to make it easier to test if an object
is available or not, which helps remove injection of
UnfoldConfiguration everywhere
2. Remove unnecessary items from StatusBar constructor. They do not
support StatusBar or otherwise part of the dependency graph. Rather
they only need to be initialized.
3. Begin work on unfold animation for keyguard

Bug: 201410717
Test: atest SystemUiTests
Change-Id: I40e280c904e38d877df424b31a9d1af90c39145e