try to disable in lots of ways

Author: scotthart

.bazelrc

@@ -21,7 +21,10 @@ build --enable_platform_specific_config=true
 build --features=external_include_paths
 
 build --per_file_copt=grpc+//@-Wno-private-header
-
+build --copt=-Wno-private-header
+build --cxxopt=-Wno-private-header
+build --host_copt=-Wno-private-header
+build --host_cxxopt=-Wno-private-header
 
 # The project requires C++ >= 17.
 build:linux --cxxopt=-std=c++17