Exempt-From-Owner-Approval: Update the OWNERS

Remove the obsolete owners from the OWNERS file and add tfiga@ and
akahuang@ as the current owners of the project.

Motivation: None of the existing owners work on this part of the project
anymore, while tfiga@ and akahuang@ have the most recent commits there.

Exempt-From-Owner-Approval, as we are having problems getting the
approvals for the same reason above.

BUG=none
TEST=none

Change-Id: Ib047654371e6eba504cc7fc4d138d3f772d6127a
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/third_party/libv4lplugins/+/1757972


Tested-by: Tomasz Figa <tfiga@chromium.org>
Reviewed-by: Heng-ruey Hsu <henryhsu@google.com>

OWNERS

-henryhsu@chromium.org
-posciak@chromium.org
-wuchengli@chromium.org
+tfiga@chromium.org
+akahuang@chromium.org