Remove obsolete binder transport interfaces (#27720)

SecurityPolicy should be mandatory

src/core/ext/transport/binder/client/channel_create.cc

@@ -76,20 +76,6 @@ void BindToOnDeviceServerService(void* jni_env_void, jobject application,
   // clang-format on
 }
 
-// CreateBinderChannel without security policy argument is deprecated
-std::shared_ptr<grpc::Channel> CreateBinderChannel(void*, jobject,
-                                                   absl::string_view,
-                                                   absl::string_view) {
-  GPR_ASSERT(0);
-  return {};
-}
-std::shared_ptr<grpc::Channel> CreateCustomBinderChannel(
-    void*, jobject, absl::string_view, absl::string_view,
-    const ChannelArguments&) {
-  GPR_ASSERT(0);
-  return {};
-}
-
 // BindToOndeviceServerService need to be called before this, in a different
 // task (due to Android API design). (Reference:
 // https://stackoverflow.com/a/3055749)

src/core/ext/transport/binder/client/channel_create.h

@@ -39,16 +39,6 @@ void BindToOnDeviceServerService(void* jni_env_void, jobject application,
                                  absl::string_view /*package_name*/,
                                  absl::string_view /*class_name*/);
 
-// CreateBinderChannel function without security policy argument. These
-// interface temporarily exists to avoid breaking the compilation.
-// TODO(mingcl): Remove these.
-std::shared_ptr<grpc::Channel> CreateBinderChannel(
-    void* jni_env_void, jobject application, absl::string_view package_name,
-    absl::string_view class_name);
-std::shared_ptr<grpc::Channel> CreateCustomBinderChannel(
-    void* jni_env_void, jobject application, absl::string_view package_name,
-    absl::string_view class_name, const ChannelArguments& args);
-
 // Need to be invoked after BindToOnDeviceServerService
 // Create a new Channel from server package name and service class name
 std::shared_ptr<grpc::Channel> CreateBinderChannel(