roll: third_party/pigweed pw_allocator: Avoid read of invalid requested size

Prior to this CL, block types which included the `BlockWithLayout`
mix-in would read the previous requested size in `DoResize`. That method
would be called as part of `Alignable::DoAllocAligned` before a
requested size had been set.

This CL also resets the padding of a detailed block to 0 on free. This
ensures the padding can never exceed the block size on allocation.

Original-Bug: 446769988
Original-Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/326312
Original-Revision: b00699103392091fa54e4b6619faa6e2200e2e6c

Rolled-Repo: https://pigweed.googlesource.com/pigweed/pigweed
Rolled-Commits: 8257af2f61c7cf..b0069910339209
Roll-Count: 1
Roller-URL: https://cr-buildbucket.appspot.com/build/8702428207209530785
GitWatcher: ignore
CQ-Do-Not-Cancel-Tryjobs: true
Change-Id: If90d06090b1bf372a0e687683cc38f869f285143
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/examples/+/326853
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 8257af2..b006991 160000
--- a/third_party/pigweed
+++ b/third_party/pigweed
@@ -1 +1 @@
-Subproject commit 8257af2f61c7cfa1a068ac8d83f0a6cc1a646574
+Subproject commit b00699103392091fa54e4b6619faa6e2200e2e6c