fix(sessions): Port PostgreSQL binary event actions migration fix to v1

src/google/adk/sessions/migration/migrate_from_sqlalchemy_pickle.py

@@ -148,9 +148,14 @@ def _row_to_event(
   actions = None
   if actions_val is not None:
     try:
-      if isinstance(actions_val, bytes):
+      # The source rows are read with raw SQL, so SQLAlchemy has no column
+      # type to coerce with and whatever the driver produced for the binary
+      # column arrives here untouched. psycopg2 produces a memoryview rather
+      # than bytes, so match every bytes-like form instead of one driver's.
+      if isinstance(actions_val, (bytes, bytearray, memoryview)):
         actions = _restricted_pickle_loads(
-            actions_val, allow_unsafe_unpickling=allow_unsafe_unpickling
+            bytes(actions_val),
+            allow_unsafe_unpickling=allow_unsafe_unpickling,
         )
       else:  # for spanner - it might return object directly
         actions = actions_val

tests/unittests/sessions/migration/test_migration.py

@@ -483,6 +483,32 @@ def test_migrate_from_sqlalchemy_pickle_ignores_non_object_json_fields():
   assert event.content is None
 
 
+@pytest.mark.parametrize("as_binary", [bytes, bytearray, memoryview])
+def test_migrate_from_sqlalchemy_pickle_reads_every_binary_column_type(
+    as_binary,
+):
+  """Pickled actions must survive whichever binary type the driver returns.
+
+  Events are read with raw SQL, so SQLAlchemy has no column type to coerce
+  with and the driver's own representation reaches the migration: psycopg2
+  returns a memoryview rather than bytes. Treating that as "some other
+  backend handed us an object" replaced the actions with an empty one while
+  the migration still reported success.
+  """
+  actions = EventActions(state_delta={"skey": 4}, escalate=True)
+
+  event = mfsp._row_to_event({
+      "id": "event-binary-actions",
+      "invocation_id": "invoke1",
+      "author": "user",
+      "timestamp": datetime(2026, 1, 1, tzinfo=timezone.utc),
+      "actions": as_binary(pickle.dumps(actions)),
+  })
+
+  assert event.actions.state_delta == {"skey": 4}
+  assert event.actions.escalate is True
+
+
 def test_migrate_from_sqlalchemy_pickle_blocks_unsafe_actions_pickle(
     tmp_path, monkeypatch
 ):