Schema Modification does not work on Input types

[qcbuyertools]

Hello,

We are trying to remove a field on an input by doing SchemaModification, but from this code it looks like proto modification only works on GraphQLObjectType instead of GraphQLInputObjectType:

rejoiner/rejoiner/src/main/java/com/google/api/graphql/rejoiner/ProtoRegistry.java

Lines 196 to 206 in cedc123

	if (mapping.get(key) instanceof GraphQLObjectType) {
	GraphQLObjectType val = (GraphQLObjectType) mapping.get(key);
	if (modifications.containsKey(key)) {
	for (TypeModification modification : modifications.get(key)) {
	val = modification.apply(val);
	}
	}
	result.put(key, val);
	} else {
	result.put(key, mapping.get(key));
	}

Is there any chance we can add support for type modification on the input type?