Grey the previously connected device preference
* For fix the TreeHugger error in pi-dev, cherry pick the ag/3935357 in
master and fix TreeHugger error.
* Add PreviouslyConnectedDevicePreferenceController to handle the preference should be
enable or disable.
Example: If there are no previously connected devices disable the preference otherwise
enable it.
* Add PreviouslyConnectedDevicePreferenceControllerTest
1. Verify the callback can be registered and unregistered
2. Verify the preference is enable when there
have more than 1 previously connected device
3. Verify the preference is disable when there
have no previously connected device
Bug: 78250052
Test: make -j50 RunSettingsRoboTests
Change-Id: I31b5d416aaf907c3bbf1cb61de6e7401463e3df7
4 files changed