Add sortableComponent abstraction

In preparation for following changes that will ensure the order of
registration (and so execution) for mutators, singletons and
pre-singletons in tests match the order in runtime this change creates
the sortableComponent interface to allow those to be sorted in the same
way without having to resort to reflection.

By moving the registration code into each component type this change
also eliminates some unnecessary duplication of that code.

Bug: 181953909
Test: m nothing
Change-Id: I597b461b966c84faaeb13e7dff765f1fadd99981