Add rounding test to orientation-event WPT

https://crrev.com/c/5249795 converted orientation-event web tests to
use WebDriver and virtual sensors. Virtual sensors follow security and
privacy requirements defined in https://www.w3.org/TR/orientation-event/#security-and-privacy.
One of these requirements include limiting the precision of values.
Specification defines that all measurements are required to be
coarsened to 0.1 degrees, 0.1 m/s^2 or 0.1 deg/s.
This change tests that requirement to limit precision is met.

Bug: 1520919
Change-Id: I58b266dc602187e2e4c4d9a3a67f12ac91136e57
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5295494
Commit-Queue: Raphael Kubo Da Costa <raphael.kubo.da.costa@intel.com>
Reviewed-by: Reilly Grant <reillyg@chromium.org>
Auto-Submit: Juha J Vainio <juha.j.vainio@intel.com>
Reviewed-by: Raphael Kubo Da Costa <raphael.kubo.da.costa@intel.com>
Cr-Commit-Position: refs/heads/main@{#1260950}