roll: third_party/pigweed pw_allocator: Add module config

This adds two new options:

* PW_ALLOCATOR_STRICT_VALIDATION, to allow optionally enabling more
expensive checks that can be used to aggressively enforce invariants
when testing. This option is not used in the current CL, but is used by
subsequent CLs.

* PW_ALLOCATOR_BLOCK_POISON_INTERVAL, to allow setting the poisoning
rate more easily from the build rather than in code via a template
parameter.

Original-Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/232211
Presubmit-Verified: CQ Bot Account <pigweed-scoped@luci-project-accounts.iam.gserviceaccount.com>
Original-Revision: d5fcc90b39ee7568855390535fa854cea8f33c95

Rolled-Repo: https://pigweed.googlesource.com/pigweed/pigweed
Rolled-Commits: a5c19d3dff644a..d5fcc90b39ee75
Roller-URL: https://ci.chromium.org/b/8736495189034539377
GitWatcher: ignore
CQ-Do-Not-Cancel-Tryjobs: true
Change-Id: Ica4d45aa996018cec4aa54cf333f4d0a15226ac9
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/examples/+/236652
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 a5c19d3..d5fcc90 160000
--- a/third_party/pigweed
+++ b/third_party/pigweed
@@ -1 +1 @@
-Subproject commit a5c19d3dff644a013df48126c4a085fd7556d715
+Subproject commit d5fcc90b39ee7568855390535fa854cea8f33c95