roll: third_party/pigweed pw_numeric: Add checked_arithmetic.h

Original-Bug: 382262919
Original-Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/253172
Original-Revision: d6827c16644efa06f524a702903397e3cc07ba4c

Rolled-Repo: https://pigweed.googlesource.com/pigweed/pigweed
Rolled-Commits: 999adb191f8f51..d6827c16644efa
Roll-Count: 1
Roller-URL: https://cr-buildbucket.appspot.com/build/8728053626705843969
GitWatcher: ignore
CQ-Do-Not-Cancel-Tryjobs: true
Change-Id: I034a32035d42593edae0eaceae928b66ba22641f
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/examples/+/255996
Commit-Queue: Pigweed Roller <pigweed-roller@pigweed-service-accounts.iam.gserviceaccount.com>
Bot-Commit: 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 999adb1..d6827c1 160000
--- a/third_party/pigweed
+++ b/third_party/pigweed
@@ -1 +1 @@
-Subproject commit 999adb191f8f512b524f0a65bd0662ac7854ef20
+Subproject commit d6827c16644efa06f524a702903397e3cc07ba4c