According to an article from CNET, around 17,000 Android apps have been tracking users even opted out of interest-based ads or Personalized Ads by linking Advertising ID to device's identifiers (i.e. MAC address, IMEI, and Android ID.)
Which is a violation of Google's policy on the use of Advertising ID:
It was also reported that these apps have already been installed on at least 100 million devices.
According to the same article, Google responded saying:
Sources:
CNET: https://www.cnet.com/news/these-android-apps-have-been-tracking-you-even-when-you-say-st