fix(docs): update the instrumentation procedure

The current testing method does not involve manually building and
running the instrumentation tests. The ones listed have diverged from
what happens. The source of trust are the jobs in CI, so update the docs
to reflect that.

Change-Id: I332f85044a36aed9ef2d87485d90861c58875e4a
Signed-off-by: Boyan Karatotev <boyan.karatotev@arm.com>
2 files changed