roll: third_party/pigweed pw_build: Search for configs from --directory

--directory is used to change the working directory, but not until
after configs are loaded, so explicitly use that if given, otherwise
use the current working directory as before.

Original-Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/357912
Presubmit-Verified: CQ Bot Account <pigweed-scoped@luci-project-accounts.iam.gserviceaccount.com>
Copybara-Verified: Copybara Prod <copybara-worker-blackhole@google.com>
Original-Revision: 7147b3c1e9ebe41b5d6ba9c0be4788555de49b9c

Rolled-Repo: https://pigweed.googlesource.com/pigweed/pigweed
Rolled-Commits: 2ccc2c8c678629..7147b3c1e9ebe4
Roll-Count: 1
Roller-URL: https://cr-buildbucket.appspot.com/build/8694993332968113969
GitWatcher: ignore
CQ-Do-Not-Cancel-Tryjobs: true
Change-Id: Iaa36fa5c595b2be6cfd025166a781692e5c1bb7e
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/examples/+/358032
Bot-Commit: Pigweed Roller <pigweed-roller@pigweed-service-accounts.iam.gserviceaccount.com>
Commit-Queue: Pigweed Roller <pigweed-roller@pigweed-service-accounts.iam.gserviceaccount.com>
Lint: Lint 🤖 <android-build-ayeaye@system.gserviceaccount.com>
diff --git a/third_party/pigweed b/third_party/pigweed
index 2ccc2c8..7147b3c 160000
--- a/third_party/pigweed
+++ b/third_party/pigweed
@@ -1 +1 @@
-Subproject commit 2ccc2c8c6786295637b6940400b4ca2f9b59c38b
+Subproject commit 7147b3c1e9ebe41b5d6ba9c0be4788555de49b9c