chore: LSC Add load statements for Proto rules

Adds required load statements for Proto rules to BUILD files.

This is a no-op as the rules are implicitly added to BUILD files via
the blaze prelude file. Explicit load statements are being added so
this injection can be removed.

For setting up Copybara transformations see: go/bazel-rules-copybara

See go/add_builtins_rule_loads

Tested:
    TAP --sample ran all affected tests and none failed
    http://test/OCL:702211513:BASE:702165998:1733209734019:1b09b2bb
PiperOrigin-RevId: 702211513

Bug: b/383533716
Change-Id: I70fc4f601993c011088ab9d0140721d59d53007a
GitOrigin-RevId: 2dccb3e8b62c96b9a82d6cdc37bfa18342e2c877

public/BUILD

@@ -1,3 +1,4 @@
+load("//third_party/protobuf/bazel:proto_library.bzl", "proto_library")
 load("//tools/build_defs/proto/cpp:cc_proto_library.bzl", "cc_proto_library")
 
 package(