docs: clarify docstring in RunQueryRequest/RunQueryResponse (#544)

* fix: change REST binding for ListDocuments to support root collection

PiperOrigin-RevId: 432504691

Source-Link: googleapis/googleapis@3db3087

Source-Link: googleapis/googleapis-gen@80f0375
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google/cloud/firestore_v1/types/common.py

@@ -60,7 +60,8 @@ class Precondition(proto.Message):
             This field is a member of `oneof`_ ``condition_type``.
         update_time (google.protobuf.timestamp_pb2.Timestamp):
             When set, the target document must exist and
-            have been last updated at that time.
+            have been last updated at that time. Timestamp
+            must be microsecond aligned.
 
             This field is a member of `oneof`_ ``condition_type``.
     """

google/cloud/firestore_v1/types/firestore.py

@@ -511,7 +511,10 @@ class RunQueryRequest(proto.Message):
 
             This field is a member of `oneof`_ ``query_type``.
         transaction (bytes):
-            Reads documents in a transaction.
+            Run the query within an already active
+            transaction.
+            The value here is the opaque transaction ID to
+            execute the query in.
 
             This field is a member of `oneof`_ ``consistency_selector``.
         new_transaction (google.cloud.firestore_v1.types.TransactionOptions):
@@ -559,8 +562,8 @@ class RunQueryResponse(proto.Message):
             was set in the request. If set, no other fields will be set
             in this response.
         document (google.cloud.firestore_v1.types.Document):
-            A query result.
-            Not set when reporting partial progress.
+            A query result, not set when reporting
+            partial progress.
         read_time (google.protobuf.timestamp_pb2.Timestamp):
             The time at which the document was read. This may be
             monotonically increasing; in this case, the previous