[quant][graph] Update dynamic quant tests to use new qconfig (#35325)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/35325
default_dynamic_qconfig now holds activation observer
Test Plan:
python test/test_quantize_script.py
Imported from OSS
Differential Revision: D20640487
fbshipit-source-id: e0b5cd36fc7a9c0dcc9020e12901b46008b3ff40
