[roll third_party/pigweed] pw_format: Add test for escaped curly brackets

Original-Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/208291
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https://pigweed.googlesource.com/pigweed/pigweed
third_party/pigweed Rolled-Commits: 6942dd5c53c11b4..4f0b1a7c4cd2ee2
Roller-URL: https://ci.chromium.org/b/8748560151643395889
GitWatcher: ignore
CQ-Do-Not-Cancel-Tryjobs: true
Change-Id: Ie8629045014d0f7ee53f6d65eea5d619f9138f3b
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/quickstart/bazel/+/208794
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 6942dd5..4f0b1a7 160000
--- a/third_party/pigweed
+++ b/third_party/pigweed
@@ -1 +1 @@
-Subproject commit 6942dd5c53c11b400d08ad89e6e11d225cc9776e
+Subproject commit 4f0b1a7c4cd2ee20f1c605be6cc8efa87deb162b