This is thread is copied from the following website. It works.
https://issueexplorer.com/issue/microsoft/IoT-For-Beginners/287
Here are the steps I took for my workaround:
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In the terminal session to the Pi within VS Code, make a backup of adc.py by typing: 
 sudo cp /usr/local/lib/python3.7/dist-packages/grove/adc.py /usr/local/lib/python3.7/dist-packages/grove/adc.py.bak (because… safety)
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In the terminal session to the Pi within VS Code, change the permissions on adc.py so that you can edit the file from within VS Code by typing 
 sudo chmod 666 /usr/local/lib/python3.7/dist-packages/grove/adc.py (This assumes you installed the python distribution patches in the same location as python3. Your mileage may vary depending on where you installed these Python packages).
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Go to the File > Open… menu to open up the Open File Or Folder dialog box. 
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Enter in /usr/local/lib/python3.7/dist-packages/grove/adc.py, then press the OK button. 
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In the adc.py file, go to approximately line 57, and change the 0x04 to 0x08 as shown below from: 
def __init__(self, address = 0x04):to: def __init__(self, address = 0x08):
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Go to the File > Save menu to Save the adc.py file. 
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In the terminal session to the Pi within VS Code, change the permissions back on adc.py by typing: 
 sudo chmod 644 /usr/local/lib/python3.7/dist-packages/grove/adc.py.
Now it works!