[keras] fixes bug in plotting (selection of ll vars)

keras.py

@@ -635,7 +635,7 @@ class PlotMulticlass(PlottingCallback, TFSummaryCallback):
                     {
                         key: importance[key]
                         for key in importance.keys()
-                        if any(key.endswith(p) for p in kinematics)
+                        if any(key.endswith(f"_{p}") for p in kinematics)
                     },
                     xlabel="Importance [AU]",
                 )