roll: third_party/pigweed 37eca3f..a4636bc (2 commits)

a4636bc:https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/243133 pw_unit_test: Fix -Waddress warning when verifying RUN_ALL_TESTS
29c5be4:https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/243718 pw_channel: Add more "Why channels" high-level docs

Rolled-Repo: https://pigweed.googlesource.com/pigweed/pigweed
Rolled-Commits: 37eca3f8c1d470..a4636bc83d6905
Roll-Count: 1
Roller-URL: https://cr-buildbucket.appspot.com/build/8733406173166781505
GitWatcher: ignore
CQ-Do-Not-Cancel-Tryjobs: true
Change-Id: I75def9c71877381dad05ebb72ef217056f27eb93
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/experimental/+/243832
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 37eca3f..a4636bc 160000
--- a/third_party/pigweed
+++ b/third_party/pigweed
@@ -1 +1 @@
-Subproject commit 37eca3f8c1d4708a8d6c8b15fb5e8934092f73ba
+Subproject commit a4636bc83d6905cb252a65d19eab4ec2478af42b