Find tzdata in the runtime module before /system

Look for the tzdata file in the runtime module before looking
in /system. It is still an open question how the removal of
tzdata will be handled, if at all. Until it is worked out it
will be duplicated.

Bug: 119293618
Bug: 119390260
Test: build / boot
Change-Id: I7e14ef41d0ec226caa595c56be61df5ecf50c382