Do not reset roundness on ExpandableOutlineView.initDimens()

Manual test steps:
- Post some notifications in different sections
- Change the wallpaper of your device
Previous behavior: Notifications no longer stayed rounded
New behavior: Notifications remain rounded

Test: atest ActivatableNotificationViewTest.roundnessShouldBeTheSame_after_onDensityOrFontScale()
Bug: 262573700
Change-Id: I12550d1201b8e43ca7af92a1ba5fd1e164446bd0