fix model_generic python templates to have valid imports for polymorphism

Author: Yousef Haggy

modules/openapi-generator/src/main/resources/python-pydantic-v1/model_generic.mustache

@@ -17,7 +17,7 @@ from typing import TYPE_CHECKING
 from importlib import import_module
 if TYPE_CHECKING:
 {{#mappedModels}}
-    from {{packageName}}.models.{{model.classVarName}} import {{modelName}}
+    from {{packageName}}.models.{{model.classFilename}} import {{modelName}}
 {{/mappedModels}}
 
 {{/discriminator}}
@@ -238,7 +238,7 @@ class {{classname}}({{#parent}}{{{.}}}{{/parent}}{{^parent}}BaseModel{{/parent}}
         object_type = cls.get_discriminator_value(obj)
         {{#mappedModels}}
         if object_type ==  '{{{modelName}}}':
-            return import_module("{{packageName}}.models.{{model.classVarName}}").{{modelName}}.from_dict(obj)
+            return import_module("{{packageName}}.models.{{model.classFilename}}").{{modelName}}.from_dict(obj)
         {{/mappedModels}}
         raise ValueError("{{{classname}}} failed to lookup discriminator value from " +
                             json.dumps(obj) + ". Discriminator property name: " + cls.__discriminator_property_name +

modules/openapi-generator/src/main/resources/python/model_generic.mustache

@@ -18,7 +18,7 @@ from typing_extensions import Self
 from typing import TYPE_CHECKING
 if TYPE_CHECKING:
 {{#mappedModels}}
-    from {{packageName}}.models.{{model.classVarName}} import {{modelName}}
+    from {{packageName}}.models.{{model.classFilename}} import {{modelName}}
 {{/mappedModels}}
 
 {{/discriminator}}
@@ -261,7 +261,7 @@ class {{classname}}({{#parent}}{{{.}}}{{/parent}}{{^parent}}BaseModel{{/parent}}
         object_type = cls.get_discriminator_value(obj)
         {{#mappedModels}}
         if object_type ==  '{{{modelName}}}':
-            return import_module("{{packageName}}.models.{{model.classVarName}}").{{modelName}}.from_dict(obj)
+            return import_module("{{packageName}}.models.{{model.classFilename}}").{{modelName}}.from_dict(obj)
         {{/mappedModels}}
 
         raise ValueError("{{{classname}}} failed to lookup discriminator value from " +