Rework gRPC status based on new rules (#1308)

As of #1214, the status codes changed and no longer line up with gRPC
status codes, so now we'll just set `StatusCode.ERROR` and store the
actual gRPC status code in the trace as `grpc.status_code`.

Specifically this: open-telemetry/opentelemetry-specification#1156

Author: alertedsnake

instrumentation/opentelemetry-instrumentation-grpc/src/opentelemetry/instrumentation/grpc/_server.py

@@ -113,8 +113,9 @@ def set_trailing_metadata(self, *args, **kwargs):
     def abort(self, code, details):
         self.code = code
         self.details = details
+        self._active_span.set_attribute("rpc.grpc.status_code", code.name)
         self._active_span.set_status(
-            Status(status_code=StatusCode(code.value[0]), description=details)
+            Status(status_code=StatusCode.ERROR, description=details)
         )
         return self._servicer_context.abort(code, details)
 
@@ -125,18 +126,16 @@ def set_code(self, code):
         self.code = code
         # use details if we already have it, otherwise the status description
         details = self.details or code.value[1]
+        self._active_span.set_attribute("rpc.grpc.status_code", code.name)
         self._active_span.set_status(
-            Status(status_code=StatusCode(code.value[0]), description=details)
+            Status(status_code=StatusCode.ERROR, description=details)
         )
         return self._servicer_context.set_code(code)
 
     def set_details(self, details):
         self.details = details
         self._active_span.set_status(
-            Status(
-                status_code=StatusCode(self.code.value[0]),
-                description=details,
-            )
+            Status(status_code=StatusCode.ERROR, description=details)
         )
         return self._servicer_context.set_details(details)
 
@@ -189,6 +188,7 @@ def _start_span(self, handler_call_details, context):
         attributes = {
             "rpc.method": handler_call_details.method,
             "rpc.system": "grpc",
+            "rpc.grpc.status_code": grpc.StatusCode.OK,
         }
 
         metadata = dict(context.invocation_metadata())