Throw error if task list is empty or task not found (#2543)

* Add more logging

* Revert import order

* Add TODO

ground/src/main/java/com/google/android/ground/ui/datacollection/DataCollectionViewModel.kt

@@ -315,7 +315,20 @@ internal constructor(
    * reversed is set, will generate the previous tasks from there.
    */
   private fun getTaskSequence(startId: String? = null, reversed: Boolean = false): Sequence<Task> {
-    val startIndex = tasks.indexOf(tasks.first { it.id == (startId ?: tasks[0].id) })
+    if (tasks.isEmpty()) {
+      error("Can't generate sequence for empty task list")
+    }
+
+    val task = tasks.filter { it.id == (startId ?: tasks[0].id) }
+
+    // TODO(#2539): Cleanup once https://github.com/google/ground-android/issues/2539 is resolved.
+    if (task.isEmpty()) {
+      error(
+        "Unable to find a task with id startId=$startId, firstTaskId=${tasks[0].id}, allTasks=${tasks.map { it.id }}"
+      )
+    }
+
+    val startIndex = tasks.indexOf(task.first())
     return if (reversed) {
         tasks.subList(0, startIndex + 1).reversed()
       } else {