Fix get_enable_high_log_scale_mode to return False instead of None for backward compatibility

Author: carlotaarvela

src/aks-preview/azext_aks_preview/managed_cluster_decorator.py

@@ -2860,6 +2860,9 @@ def get_enable_high_log_scale_mode(self) -> Union[bool, None]:
             return True
 
         # If container network logs are not being enabled, return the original value
+        # Return False if not explicitly set to maintain backward compatibility with base class
+        if enable_high_log_scale_mode is None:
+            return False
         return enable_high_log_scale_mode
 
     def _get_enable_vpa(self, enable_validation: bool = False) -> bool:

src/aks-preview/azext_aks_preview/tests/latest/test_managed_cluster_decorator.py

@@ -4578,15 +4578,33 @@ def test_get_disable_gateway_api(self):
         self.assertEqual(disable_gateway_api_3, False)
 
     def test_get_enable_high_log_scale_mode_default(self):
-        """Test default behavior when no container network logs or high log scale mode is specified."""
+        """Test default behavior when no container network logs or high log scale mode is specified.
+        
+        When enable_high_log_scale_mode is not explicitly set and container network logs are not enabled,
+        the method should return False (not None) to maintain backward compatibility with the base class.
+        """
         ctx = AKSPreviewManagedClusterContext(
             self.cmd,
             AKSManagedClusterParamDict({}),
             self.models,
             decorator_mode=DecoratorMode.CREATE,
         )
         result = ctx.get_enable_high_log_scale_mode()
-        self.assertIsNone(result)
+        self.assertFalse(result)
+
+    def test_get_enable_high_log_scale_mode_explicit_false_without_cnl(self):
+        """Test when user explicitly sets enable_high_log_scale_mode to False without container network logs.
+        
+        This should return False without raising any errors since container network logs are not enabled.
+        """
+        ctx = AKSPreviewManagedClusterContext(
+            self.cmd,
+            AKSManagedClusterParamDict({"enable_high_log_scale_mode": False}),
+            self.models,
+            decorator_mode=DecoratorMode.CREATE,
+        )
+        result = ctx.get_enable_high_log_scale_mode()
+        self.assertFalse(result)
 
     def test_get_enable_high_log_scale_mode_explicit_true(self):
         """Test when user explicitly enables high log scale mode."""