3 separate places had hardcoded values for the t-h-t directory. Many
values are/will be shared, this patch consolidates them to avoid having
them diverge in the future.
Depends-On: I98e19cc29d69cbd6636cd4ce77a07c7a0e3dc048
Change-Id: I205569f4be0bcee2b284048dec7ddf0b28bbd8a1