strip_package: source common.sh directly

We're no longer installing this.

BUG=None
TEST=CQ passed

Change-Id: I7a3906763e13e65374c26bb462bbe74b14d0b939
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/dev-util/+/1856661
Reviewed-by: Amin Hassani <ahassani@chromium.org>
Tested-by: Mike Frysinger <vapier@chromium.org>
1 file changed