Most blocks samples for TensorFlow can't be used for a different model

[lizlooney]

There are 4 blocks samples for TensorFlow:

1. ConceptTensorFlowObjectDetection
2. ConceptTensorFlowObjectDetectionWebcam
3. ConceptTensorFlowObjectDetectionSwitchableCameras
4. ConceptTensorFlowObjectDetectionCustomModel

If a team starts with any of the first 3 samples and then wants to use a different model, they have to replace all the TensorFlow blocks in their opmode.