Bazel: move ./auto/configure artifacts to "bazel-objs" directory.
Bazel: move ./auto/configure artifacts to "bazel-objs" directory.

This prevents artifacts from the "objs" directory in the source tree
from being used instead of those generated by Bazel when building on
an OS without Bazel sandbox.

Change-Id: If20338907989302c5e9fd02eef12595312a0ada6
Signed-off-by: Piotr Sikora <ba6f3a1a6d7e1ecae91b31e93969cc392fbd0fdd@google.com>
Reviewed-on: https://nginx-review.googlesource.com/1270
Reviewed-by: Martin Maly <e8c0ee8c9f9b3872b26a60336f45a625d658b541@google.com>

firebase/nginx,firebase/nginx,firebase/nginx,firebase/nginx