roll: third_party/pigweed pw_bluetooth_proxy: Fix multiplexer stall from intercepted credit events

The command multiplexer can get stuck and stop sending HCI commands.
This happens when an event that provides command credits, such as
CommandComplete or CommandStatus, is swallowed by an event interceptor
and not propagated. As a result, the multiplexer's credit count is never
updated and it stops sending commands. This change fixes the issue by
updating the command credits and processing the command queue before
invoking any event interceptors. This ensures that the credit count is
correctly maintained even if the event is not forwarded to the host. The
UpdateNumHciCommandPackets function has been removed, and its logic has
been integrated into OnH4HciEventReceived. A new test,
TestCreditRecoveredWhenIntercepted, has been added to verify that
credits are correctly handled when an event is intercepted.

Original-Bug: 502820296
Test: bazelisk test //pw_bluetooth_proxy/...
Original-Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/398232
Original-Revision: 5a5b2b0ab414a1f07c2dc5fcee195ee327835639

Rolled-Repo: https://pigweed.googlesource.com/pigweed/pigweed
Rolled-Commits: 20b6ca7ab93a5e..5a5b2b0ab414a1
Roll-Count: 1
Roller-URL: https://cr-buildbucket.appspot.com/build/8683945488316315521
GitWatcher: ignore
CQ-Do-Not-Cancel-Tryjobs: true
Change-Id: I32dc59a29b7879e3e4191820aedf7e354081bfcb
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/examples/+/400633
diff --git a/third_party/pigweed b/third_party/pigweed
index 20b6ca7..5a5b2b0 160000
--- a/third_party/pigweed
+++ b/third_party/pigweed
@@ -1 +1 @@
-Subproject commit 20b6ca7ab93a5e1114eb6db5b3582dcab9b7a646
+Subproject commit 5a5b2b0ab414a1f07c2dc5fcee195ee327835639