* Support comparing icon sets with a custom equivalence (needed because AppEntry doesn't implement equals(), and somewhat tricky because CircularIconPreference itself is not generic).
* Use final icons for allowed sounds.
* Use final appearance for +n icon.
Test: atest com.android.settings.notification.modes
Bug: 346551087
Flag: android.app.modes_ui
Change-Id: Iceadf4a182e607111afb72ff36bca872a62ae040
(Some icons are temporary, until we get the final assets)
Also some fixes/improvements to CircularIconsPreference:
* Show the correct placeholder and +N icons.
* Fix the displayIcons-before-measure case (global layout listener was incorrect).
* Properly cancel pending image load futures (field didn't point to the actual future).
* Don't reload icons if it's the same set (depends on equals() for the items, so unfortunately doesn't work for AppEntry yet).
Test: atest com.android.settings.notification.modes
Bug: 346551087
Flag: android.app.modes_ui
Change-Id: I9d029a5fdd785ada4e2ba4d8a90eba72b5fb9085
(Several things pending, such as the +n icon and the correct pending icons, but it's a start).
Test: atest com.android.settings.notification.modes
Bug: 346551087
Flag: android.app.modes_ui
Change-Id: Ifd2ab6a8bb447739dc8ffe400c3960779d477fd6
