TEST_MAPPING for time / zone detector services

Add TEST_MAPPING files for time / time zone detector services.

https://yaqs.corp.google.com/eng/q/5733889948123136 seems to suggest
there may be some value in doing this, even though the code under test
is covered by TEST_MAPPING already. Currently assumed to be needed to
catch test-only changes.

Bug: 299614090
Bug: 182461754
Test: treehugger only
Change-Id: I4bacb470fe294aa4263ee7b2e507c18ea7c7ece7