define cache in API layer

Author: ohmayr

gapic/schema/api.py

@@ -456,6 +456,7 @@ def disambiguate_keyword_sanitize_fname(
         # type into the proto file that defines an LRO.
         # We just load all the APIs types first and then
         # load the services and methods with the full scope of types.
+        context_cache = {}
         pre_protos: Dict[str, Proto] = dict(prior_protos or {})
         for fd in file_descriptors:
             fd.name = disambiguate_keyword_sanitize_fname(fd.name, pre_protos)