roll: third_party/pigweed: pw_bluetooth_sapphire: Add testing Bazel unit test target

Original-Bug: b/359241441
Test: bazel test //pw_bluetooth_sapphire/host/...
      --platforms=//pw_unit_test:googletest_platform
      --@pigweed//pw_unit_test:backend=@pigweed//pw_unit_test:googletest
Original-Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/234231

https://pigweed.googlesource.com/pigweed/pigweed
third_party/pigweed Rolled-Commits: 7e9104fb19c00c3..196272619238281
Roller-URL: https://ci.chromium.org/b/8737611071551157809
GitWatcher: ignore
CQ-Do-Not-Cancel-Tryjobs: true
Change-Id: I887a828e87eebabdcc5bbbf3e88156e1967845c8
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/experimental/+/233965
Lint: Lint 🤖 <android-build-ayeaye@system.gserviceaccount.com>
Commit-Queue: Pigweed Roller <pigweed-roller@pigweed-service-accounts.iam.gserviceaccount.com>
Bot-Commit: Pigweed Roller <pigweed-roller@pigweed-service-accounts.iam.gserviceaccount.com>
diff --git a/third_party/pigweed b/third_party/pigweed
index 7e9104f..1962726 160000
--- a/third_party/pigweed
+++ b/third_party/pigweed
@@ -1 +1 @@
-Subproject commit 7e9104fb19c00c3eb0b82bfacc955219b830e618
+Subproject commit 19627261923828145508a9185d31c290c27325b7