fix: add cleanup test to distributed counters

Author: crwilcox

firestore/cloud-client/distributed_counters_test.py

@@ -47,3 +47,15 @@ def test_distributed_counters(fs_client):
     counter.increment_counter(doc_ref)
     counter.increment_counter(doc_ref)
     assert counter.get_count(doc_ref) == 2
+
+
+def test_distributed_counters_cleanup(fs_client):
+    col = fs_client.collection("dc_samples")
+    doc_ref = col.document("distributed_counter")
+
+    shards = doc_ref.collection("shards").list_documents()
+    shards_list = [shard for shard in shards]
+    for shard in shards_list:
+        shard.delete()
+
+    doc_ref.delete()