Rename 26.xml=>1.xml, 27.xml=>2.xml

FCM Version uses a different set of numbers than the SDK level.
This is to decouple the connection between them; it is not required
to have one FCM Version per SDK level.

Test: build test
Test: boots

Bug: 69636193
Change-Id: I62a29b702271d8a7ca8ae80e545a6d2e3b46fdcf
Merged-In: I62a29b702271d8a7ca8ae80e545a6d2e3b46fdcf