Fix foward declaration duplication
diff --git a/gRPC-Core.podspec b/gRPC-Core.podspec
index 8869bec..1a1b9fc 100644
--- a/gRPC-Core.podspec
+++ b/gRPC-Core.podspec
@@ -146,6 +146,7 @@
                       'include/grpc/impl/codegen/atm_gcc_atomic.h',
                       'include/grpc/impl/codegen/atm_gcc_sync.h',
                       'include/grpc/impl/codegen/atm_windows.h',
+                      'include/grpc/impl/codegen/exec_ctx_fwd.h',
                       'include/grpc/impl/codegen/gpr_types.h',
                       'include/grpc/impl/codegen/port_platform.h',
                       'include/grpc/impl/codegen/slice.h',
@@ -172,6 +173,7 @@
                       'include/grpc/impl/codegen/atm_gcc_atomic.h',
                       'include/grpc/impl/codegen/atm_gcc_sync.h',
                       'include/grpc/impl/codegen/atm_windows.h',
+                      'include/grpc/impl/codegen/exec_ctx_fwd.h',
                       'include/grpc/impl/codegen/gpr_types.h',
                       'include/grpc/impl/codegen/port_platform.h',
                       'include/grpc/impl/codegen/slice.h',