Finish including Beam version details in MongoDB handshake (#36961)

* Revert #36949

* Update _MongoSink

Author: NoahStapp

sdks/python/apache_beam/io/mongodbio.py

@@ -269,6 +269,12 @@ def __init__(
         **self.spec,
         driver=DriverInfo("Apache Beam", beam.__version__))
 
+    if "driver" not in self.spec:
+      self.spec["driver"] = DriverInfo(
+          name="Apache Beam",
+          version=beam.__version__,
+      )
+
   def estimate_size(self):
     with MongoClient(self.uri, **self.spec) as client:
       return client[self.db].command("collstats", self.coll).get("size")
@@ -783,6 +789,12 @@ def __init__(self, uri=None, db=None, coll=None, extra_params=None):
     self.spec = extra_params
     self.client = None
 
+    if "driver" not in self.spec:
+      self.spec["driver"] = DriverInfo(
+          name="Apache Beam",
+          version=beam.__version__,
+      )
+
   def write(self, documents):
     if self.client is None:
       self.client = MongoClient(host=self.uri, **self.spec)