roll: third_party/pigweed 4fa03e9..6784a0d (3 commits)

6784a0d:https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/281855 pw_channel: Document inheritance pattern; discourage SiblingCast
df60e9e:https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/283973 pw_env_setup: Update CIPD pin
edd09be:https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/282892 pw_perf_test: Only enable if the timer backend is set

Rolled-Repo: https://pigweed.googlesource.com/pigweed/pigweed
Rolled-Commits: 4fa03e9fd2a527..6784a0d32e4760
Roll-Count: 1
Roller-URL: https://cr-buildbucket.appspot.com/build/8717494755115940097
GitWatcher: ignore
CQ-Do-Not-Cancel-Tryjobs: true
Change-Id: I836f2395a3d18fcde33a01f1cdacf669dc564c2a
Reviewed-on: https://pigweed-review.googlesource.com/c/gonk/+/284097
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 4fa03e9..6784a0d 160000
--- a/third_party/pigweed
+++ b/third_party/pigweed
@@ -1 +1 @@
-Subproject commit 4fa03e9fd2a527aeade33989e7d20f3273b2a01b
+Subproject commit 6784a0d32e4760607ad854d05170195f928bfea3