Since the 26th of February , the Android companion app constantly sends its users’ GPS coordinates to Google. It does that by continually requesting reverse geocoding (i.e., “translate GPS position to street address”), which on virtually all Android devices  is done via Google Maps. There is no warning about this, there is no way of turning it off (short of revoking the HA app’s location permission, which of course means that your HA instance can’t use your phone as a device tracker anymore).
And since I’ve had the “but you’re leaking your location to Google anyways” discussion three times now (twice on Discord, #general and #android, once on GitHub): No, if you configure your Android correctly, you’re not. Turn off location history, turn off Wifi-Assisted positioning, and your phone should (read: if Google is not lying) not send location information to Google servers. I agree that Google’s default settings (both are turned on by default) are evil. However, even evil Google offers to turn that off, contrary to the HA companion app.
I’ve opened a GitHub issue about this here: https://github.com/home-assistant/android/issues/582
 PR #476: https://github.com/home-assistant/android/pull/476
 Minus those which do not have the Google Services Framework installed