feat: add the name of the reservation the job was submitted to as a field (#11643)

Co-authored-by: Owl Bot <gcf-owl-bot[bot]@users.noreply.github.com>

Author: gcf-owl-bot[bot]

packages/google-cloud-bigquery-logging/google/cloud/bigquery_logging_v1/types/audit_data.py

@@ -1291,6 +1291,9 @@ class JobStatistics(proto.Message):
             populated. Aggregate usage of all jobs submitted
             to a reservation should provide a more reliable
             indicator of reservation imbalance.
+        reservation (str):
+            Reservation name or "unreserved" for
+            on-demand resource usage.
         referenced_tables (MutableSequence[google.cloud.bigquery_logging_v1.types.TableName]):
             The first N tables accessed by the query job. Older queries
             that reference a large number of tables may not have all of
@@ -1375,6 +1378,10 @@ class ReservationResourceUsage(proto.Message):
         number=14,
         message=ReservationResourceUsage,
     )
+    reservation: str = proto.Field(
+        proto.STRING,
+        number=16,
+    )
     referenced_tables: MutableSequence["TableName"] = proto.RepeatedField(
         proto.MESSAGE,
         number=9,