Bring RFH/RVH unit tests closer to reality of how RF/RV are initialized

This is an attempt at relanding https://codereview.chromium.org/1151973005,
which broke official builds due to RlzLibTest unit tests failing.
The initial patchset is identical to the previously committed CL and
subsequent uploads are changes made to fix the failures.

BUG=357747
TEST=all unit tests continue passing

Review URL: https://codereview.chromium.org/1156023006

Cr-Commit-Position: refs/heads/master@{#332380}
13 files changed