Force last owner of a room to pass ownership when leaving (#5094)

* Move `ChangeRoles*` classes to their own module so they can be shared

* Hook the change roles screen to the leave room action, add confirmation dialogs

* Use enum instead of sealed interface for `ChangeRoomMemberRolesListType`

* Try to improve communications between nodes

* refactor (leave room) : makes sure to expose only necessary code from api module

* Add `:libraries:previewutils` module to share some test fixtures used for UI previews

* Update screenshots

---------

Co-authored-by: ElementBot <android@element.io>
Co-authored-by: ganfra <francoisg@matrix.org>

appnav/src/main/kotlin/io/element/android/appnav/LoggedInEventProcessor.kt

@@ -14,6 +14,7 @@ import io.element.android.libraries.matrix.api.timeline.item.event.MembershipCha
 import io.element.android.libraries.ui.strings.CommonStrings
 import kotlinx.coroutines.CoroutineScope
 import kotlinx.coroutines.Job
+import kotlinx.coroutines.flow.distinctUntilChanged
 import kotlinx.coroutines.flow.filter
 import kotlinx.coroutines.flow.launchIn
 import kotlinx.coroutines.flow.onEach
@@ -28,6 +29,7 @@ class LoggedInEventProcessor @Inject constructor(
     fun observeEvents(coroutineScope: CoroutineScope) {
         observingJob = roomMembershipObserver.updates
             .filter { !it.isUserInRoom }
+            .distinctUntilChanged()
             .onEach {
                 when (it.change) {
                     MembershipChange.LEFT -> displayMessage(CommonStrings.common_current_user_left_room)