Remove default value for lambda.

We enforce a value to be provided and it's better for code coverage.

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

@@ -134,8 +134,8 @@ class RootFlowNode @AssistedInject constructor(
 
     private suspend fun restoreSessionIfNeeded(
         sessionId: SessionId,
-        onFailure: () -> Unit = {},
-        onSuccess: (SessionId) -> Unit = {},
+        onFailure: () -> Unit,
+        onSuccess: (SessionId) -> Unit,
     ) {
         matrixClientsHolder.getOrRestore(sessionId)
             .onSuccess {
@@ -149,8 +149,8 @@ class RootFlowNode @AssistedInject constructor(
     }
 
     private suspend fun tryToRestoreLatestSession(
-        onSuccess: (SessionId) -> Unit = {},
-        onFailure: () -> Unit = {}
+        onSuccess: (SessionId) -> Unit,
+        onFailure: () -> Unit
     ) {
         val latestSessionId = authenticationService.getLatestSessionId()
         if (latestSessionId == null) {

appnav/src/main/kotlin/io/element/android/appnav/root/RootView.kt

@@ -35,8 +35,8 @@ import io.element.android.services.apperror.impl.AppErrorView
 @Composable
 fun RootView(
     state: RootState,
+    onOpenBugReport: () -> Unit,
     modifier: Modifier = Modifier,
-    onOpenBugReport: () -> Unit = {},
     children: @Composable BoxScope.() -> Unit,
 ) {
     Box(
@@ -69,7 +69,10 @@ fun RootView(
 @PreviewsDayNight
 @Composable
 internal fun RootPreview(@PreviewParameter(RootStateProvider::class) rootState: RootState) = ElementPreview {
-    RootView(rootState) {
+    RootView(
+        state = rootState,
+        onOpenBugReport = {},
+    ) {
         Text("Children")
     }
 }