chore(python): exclude grpcio==1.49.0rc1 in tests (#1556)

chore(python): exclude  in tests

Author: parthea

synthtool/gcp/templates/python_library/noxfile.py.j2

@@ -209,7 +209,9 @@ def unit(session):
 def install_systemtest_dependencies(session, *constraints):
 
     # Use pre-release gRPC for system tests.
-    session.install("--pre", "grpcio")
+    # Exclude version 1.49.0rc1 which has a known issue.
+    # See https://github.com/grpc/grpc/pull/30642
+    session.install("--pre", "grpcio!=1.49.0rc1")
 
     session.install(*SYSTEM_TEST_STANDARD_DEPENDENCIES, *constraints)
 
@@ -379,7 +381,8 @@ def prerelease_deps(session):
         # dependency of grpc
         "six",
         "googleapis-common-protos",
-        "grpcio",
+        # Exclude version 1.49.0rc1 which has a known issue. See https://github.com/grpc/grpc/pull/30642
+        "grpcio!=1.49.0rc1",
         "grpcio-status",
         "google-api-core",
         "proto-plus",