Replace bundled Google Cloud protobuf imports with system packages.
The Cloud Logging tailing implementation imports generated protobuf
modules to register message descriptors used when decoding log entries.
Replace the bundled App Engine, BigQuery, and IAM protobuf imports with
their corresponding system-installed Google Cloud client libraries.
Preserve the existing imports for protobuf modules that are already
provided by system packages.
--- ../lib/googlecloudsdk/api_lib/logging/tailing.py
+++ ../lib/googlecloudsdk/api_lib/logging/tailing.py
@@ -20,13 +20,12 @@
 import datetime
 
 # pylint: disable=unused-import, type imports needed for gRPC
-import google.appengine.logging.v1.request_log_pb2
-import google.appengine.v1.audit_data_pb2
-import google.appengine.v1beta.audit_data_pb2
-import google.cloud.appengine_v1alpha.proto.audit_data_pb2
+# Import protobuf types to register descriptors for decoding log entries.
+from google.cloud.appengine_admin_v1.types import audit_data as appengine_audit_data
+from google.cloud.appengine_logging_v1.types import RequestLog
+from google.cloud.bigquery_logging_v1.types import AuditData
+from google.cloud.iam_admin_v1.types import audit_data
 import google.cloud.audit.audit_log_pb2
-import google.cloud.bigquery.logging.v1.audit_data_pb2
-import google.iam.admin.v1.audit_data_pb2
 import google.iam.v1.logging.audit_data_pb2
 import google.type.money_pb2
 # pylint: enable=unused-import