Update transition matcher to support a final transform before returning the matching transition

This is used by the quickswitch transition extractor to merge the two final transitions the closing and open next app into a single transition that the rest of the FaaS pipeline can handle.

Test: atest FlickerLibTest
Bug: 265014142
Change-Id: Ic63f200398755b7981f70a040fdf85cd6389d2b0