roll: third_party/pigweed pw_thread: Introduce pw::Thread and pw::Thread::id

- Introduce a pw::Thread alias, which new code should use. Will rename
  pw::thread::Thread in a separate commit since it involves updating all
  backends.
- Add a pw::Thread::id alias for pw::thread::Id for consistency with
  std::thread.

Original-Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/236796
Original-Revision: f1070484e7d2f4e429332c6d8520a3676b8cb965

Rolled-Repo: https://pigweed.googlesource.com/pigweed/pigweed
Rolled-Commits: 34513322e16370..f1070484e7d2f4
Roller-URL: https://ci.chromium.org/b/8735703741048351473
GitWatcher: ignore
CQ-Do-Not-Cancel-Tryjobs: true
Change-Id: I4d55549c7ba8b1e769e04755cce623dcba96040d
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/examples/+/238213
Bot-Commit: Pigweed Roller <pigweed-roller@pigweed-service-accounts.iam.gserviceaccount.com>
Lint: Lint 🤖 <android-build-ayeaye@system.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 3451332..f107048 160000
--- a/third_party/pigweed
+++ b/third_party/pigweed
@@ -1 +1 @@
-Subproject commit 34513322e16370670a4816e7affcf56cd9b50797
+Subproject commit f1070484e7d2f4e429332c6d8520a3676b8cb965