run-test-jar: Reduce environment passed to tests.

Reduce the environment to only what is actually needed.
We have been passing everything, including the user's
terminal variables until now.

This makes the tests more hermetic and reduces the
environment that is logged with the saved commands.
It also brings the host and targets code path together.

Test: test.py -b -r --all-target
Change-Id: I13f1b8cd57dfb725d32d861a2f9e50ece4077e98
1 file changed