Add a class/test to keep unbundled code working

Add a class/test for libcore.util.TimeZone to keep unbundled code
working. Robolectric and SUW in google3 have hardcoded the location of
libcore.util.TimeZoneFinder. It was recently moved to libcore.timezone
under bug 119026403. This keeps just enough API in the old location
until the various non-platform dependencies have updated.

[Chery-pick note: This is also required on pi-dev-plus-aosp to keep
SUW, which is still in the Android tree in pi, compiling]

Bug: 119026403
Bug: 119921242
Bug: 116544863
Test: build / ran new test with vogar
Merged-In: I6a747273a6abda96ce7a9c30a3bbd250832258f7
Change-Id: I6a747273a6abda96ce7a9c30a3bbd250832258f7
(cherry picked from commit 1b7fdf1841b8ebd1e5d7af5b47fa78cc8646ad04)
3 files changed