[third_party/pigweed] Roll 4 commits

6ac2d4b370be1ee pw_format: Add initial support for untyped specifi
04b24a89a24be81 bazel: Localize backend label flags
130004ab3b161b9 pw_libc: Define LIBC_FAST_MATH for the faster inte
e58a9ad72c86c4c pw_build_android: Add new utils module

https://pigweed.googlesource.com/pigweed/pigweed
third_party/pigweed Rolled-Commits: 64c48347cf7ccbd..6ac2d4b370be1ee
Roller-URL: https://ci.chromium.org/b/8753500362498814097
GitWatcher: ignore
CQ-Do-Not-Cancel-Tryjobs: true
Change-Id: I946a376bda9a3fe83e0982defb8bc41cb329a7c1
Reviewed-on: https://pigweed-review.googlesource.com/c/gonk/+/196432
Bot-Commit: Pigweed Roller <pigweed-roller@pigweed-service-accounts.iam.gserviceaccount.com>
Commit-Queue: Pigweed Roller <pigweed-roller@pigweed-service-accounts.iam.gserviceaccount.com>
diff --git a/third_party/pigweed b/third_party/pigweed
index 64c4834..6ac2d4b 160000
--- a/third_party/pigweed
+++ b/third_party/pigweed
@@ -1 +1 @@
-Subproject commit 64c48347cf7ccbdc6fbdfbc044b2a689911a7d13
+Subproject commit 6ac2d4b370be1eef6bbc1fa0b5951fc60df04af9