chore(bazel): update protobuf to v3.21.3 (#204)

* chore(bazel): update protobuf to v3.21.3

chore(bazel): update gax-java to 2.18.4

PiperOrigin-RevId: 463115700

Source-Link: googleapis/googleapis@52130a9

Source-Link: googleapis/googleapis-gen@6a4d9d9
Copy-Tag: eyJwIjoiLmdpdGh1Yi8uT3dsQm90LnlhbWwiLCJoIjoiNmE0ZDlkOWJiM2FmYjIwYjBmNWZhNGY1ZDlmNjc0MGIxZDBlYjE5YSJ9

* 🦉 Updates from OwlBot post-processor

See https://github.com/googleapis/repo-automation-bots/blob/main/packages/owl-bot/README.md

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

packages/google-cloud-memcache/google/cloud/memcache_v1/services/cloud_memcache/async_client.py

@@ -908,9 +908,6 @@ async def sample_delete_instance():
 
  }
 
- The JSON representation for Empty is empty JSON
- object {}.
-
  """
  # Create or coerce a protobuf request object.
  # Quick check: If we got a request object, we should *not* have

packages/google-cloud-memcache/google/cloud/memcache_v1/services/cloud_memcache/client.py

@@ -1131,9 +1131,6 @@ def sample_delete_instance():
 
  }
 
- The JSON representation for Empty is empty JSON
- object {}.
-
  """
  # Create or coerce a protobuf request object.
  # Quick check: If we got a request object, we should *not* have

packages/google-cloud-memcache/google/cloud/memcache_v1beta2/services/cloud_memcache/async_client.py

@@ -911,9 +911,6 @@ async def sample_delete_instance():
 
  }
 
- The JSON representation for Empty is empty JSON
- object {}.
-
  """
  # Create or coerce a protobuf request object.
  # Quick check: If we got a request object, we should *not* have

packages/google-cloud-memcache/google/cloud/memcache_v1beta2/services/cloud_memcache/client.py

@@ -1134,9 +1134,6 @@ def sample_delete_instance():
 
  }
 
- The JSON representation for Empty is empty JSON
- object {}.
-
  """
  # Create or coerce a protobuf request object.
  # Quick check: If we got a request object, we should *not* have