roll: third_party/pigweed pw_rpc: Update soong rules for pwpb & pwpb_rpc

1. Pass `--proto-path` for each proto file
2. `--compile_dir` is no longer required (pwrev.dev/278432), remove

Original-Bug: 406014819
Test: presubmit

Original-Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/278532
Presubmit-Verified: CQ Bot Account <pigweed-scoped@luci-project-accounts.iam.gserviceaccount.com>
Original-Revision: 964608167ffcd644275d127e9b928639190970e3

Rolled-Repo: https://pigweed.googlesource.com/pigweed/pigweed
Rolled-Commits: abd0403e61717e..964608167ffcd6
Roll-Count: 1
Roller-URL: https://cr-buildbucket.appspot.com/build/8718952885461586609
GitWatcher: ignore
CQ-Do-Not-Cancel-Tryjobs: true
Change-Id: If596f4ffc2daa2bcd7249bcbb455e9436b50a0b1
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/examples/+/280194
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 abd0403..9646081 160000
--- a/third_party/pigweed
+++ b/third_party/pigweed
@@ -1 +1 @@
-Subproject commit abd0403e61717e051558bc1d4505b2744e91bbce
+Subproject commit 964608167ffcd644275d127e9b928639190970e3