Retry retrieving ipconfig

There may be a small race that occurs between the acquisition of a
lease and the ipconfig visibility.  Spend a few iterations retrying
before giving up.

BUG=chromium:419006
TEST=Run this test (for regressions).

Change-Id: I513338baf5a901fcaadb56cac26cf7a01a975fe8
Reviewed-on: https://chromium-review.googlesource.com/227896
Reviewed-by: Peter Qiu <zqiu@chromium.org>
Commit-Queue: Paul Stewart <pstew@chromium.org>
Tested-by: Paul Stewart <pstew@chromium.org>
1 file changed