arc-build: bump ebuild version to 0.0.3-r15

This is required to make sure builders pick up on the change from
https://crrev.com/i/3144360 and make sure the two CLs are submitted at
the same time.

BUG=b:156569377
TEST=`cros tryjob` on rammus-arc-r with the relevant CLs together

Cq-Depend: chrome-internal:3144360
Cq-Depend: chromium:2286749
Change-Id: I606ec9d0f34f8c0d470a6b8dc112ac0017596ade
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/overlays/chromiumos-overlay/+/2286975
Tested-by: Morg <morg@chromium.org>
Auto-Submit: Morg <morg@chromium.org>
Reviewed-by: Lepton Wu <lepton@chromium.org>
Commit-Queue: Morg <morg@chromium.org>
1 file changed