fix: Allow None for auto_assign to handle NULL values from database (#1980)

Author: sricharan-varanasi

src/apps/activities/domain/activity.py

@@ -155,7 +155,7 @@ class ActivityOrFlowWithAssignmentsPublic(ActivityOrFlowBasicInfoPublic):
 class ActivityBaseInfo(ActivityMinimumInfo, InternalModel):
     contains_response_types: list[ResponseType]
     item_count: int
-    auto_assign: bool
+    auto_assign: bool | None = True
 
 
 class ActivitySubjectMetadata(PublicModel):

src/apps/activity_flows/domain/flow.py

@@ -43,7 +43,7 @@ class FlowBaseInfo(InternalModel):
     order: int
     is_hidden: bool | None = False
     activity_ids: list[uuid.UUID] = Field(default_factory=list)
-    auto_assign: bool
+    auto_assign: bool | None = True
 
 
 class FlowSingleLanguageMobileDetailPublic(FlowBaseInfo, InternalModel):