[roll third_party/pigweed] pw_protobuf_compiler: Fix bazel build issues

Before this CL, the bazel version of the pw_proto_library rule would
attempt to use a descriptor database to manage imports in proto files.
This is way overkill for the expected use cases for pw_protobuf, as we
don't expect large dependency graphs of proto files which could slow
down the build.

In addition, the `transitive_descriptor_sets` was listing the direct
proto, creating a circular dependency.

One more bug fix is included to allow use of pw_proto_library in
downstream projects by removing the mapping to short_path for the source
proto files passed to protoc. The short_path doesn't work when
referenced from an external repoistory.

Original-Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/153271

https://pigweed.googlesource.com/pigweed/pigweed
third_party/pigweed Rolled-Commits: 50bccd7de721a91..b3ce380a484701b
Roller-URL: https://ci.chromium.org/b/8776382300411964881
GitWatcher: ignore
CQ-Do-Not-Cancel-Tryjobs: true
Change-Id: I09cfa77f54193ff842887f09641be4ec27ab400a
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/experimental/+/154092
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 50bccd7..b3ce380 160000
--- a/third_party/pigweed
+++ b/third_party/pigweed
@@ -1 +1 @@
-Subproject commit 50bccd7de721a91aa80bc1b767a7a4c37789ddb0
+Subproject commit b3ce380a484701b09c45dc43374369f1cc37c4cf