Could you please try to pip install tflite-model-maker-nightly instead of tflite-model-maker without !pip install tensorflow==2.5.0?
This should resolve the issue of evaluate_tflite. However, the exported TFLite model under model-maker-nightly version is not compatible with ObjectDetector under TFLite Task library 7 since the output order is changed. We’re WIP to support such case.