Reset in-progress topic selection upon saving

Previously, the in-progress topic selection wasn't reset upon saving. This meant that clearing out the selected topics (from the topics tab) would bring back the topic selection that was last used.

Bug: 228050946

Change-Id: I3d52baf6396b41e2116f38c89a79b419c90c63b5

feature-foryou/src/main/java/com/google/samples/apps/nowinandroid/feature/foryou/ForYouViewModel.kt

@@ -169,6 +169,11 @@ class ForYouViewModel @Inject constructor(
 
         viewModelScope.launch {
             topicsRepository.setFollowedTopicIds(inProgressTopicSelection)
+
+            // Clear out the in-progress selection after saving it
+            withMutableSnapshot {
+                inProgressTopicSelection = emptySet()
+            }
         }
     }
 }

feature-foryou/src/test/java/com/google/samples/apps/nowinandroid/feature/foryou/ForYouViewModelTest.kt

@@ -328,6 +328,69 @@ class ForYouViewModelTest {
             }
     }
 
+    @Test
+    fun topicSelectionIsResetAfterSavingTopicsAndRemovingThem() = runTest {
+        viewModel.uiState
+            .test {
+                awaitItem()
+                topicsRepository.sendTopics(sampleTopics)
+                topicsRepository.setFollowedTopicIds(emptySet())
+                newsRepository.sendNewsResources(sampleNewsResources)
+
+                awaitItem()
+                viewModel.updateTopicSelection(1, isChecked = true)
+
+                awaitItem()
+                viewModel.saveFollowedTopics()
+
+                awaitItem()
+                topicsRepository.setFollowedTopicIds(emptySet())
+
+                assertEquals(
+                    ForYouFeedUiState.PopulatedFeed.FeedWithTopicSelection(
+                        topics = listOf(
+                            FollowableTopic(
+                                topic = Topic(
+                                    id = 0,
+                                    name = "Headlines",
+                                    shortDescription = "",
+                                    longDescription = "long description",
+                                    url = "URL",
+                                    imageUrl = "image URL",
+                                ),
+                                isFollowed = false
+                            ),
+                            FollowableTopic(
+                                topic = Topic(
+                                    id = 1,
+                                    name = "UI",
+                                    shortDescription = "",
+                                    longDescription = "long description",
+                                    url = "URL",
+                                    imageUrl = "image URL",
+                                ),
+                                isFollowed = false
+                            ),
+                            FollowableTopic(
+                                topic = Topic(
+                                    id = 2,
+                                    name = "Tools",
+                                    shortDescription = "",
+                                    longDescription = "long description",
+                                    url = "URL",
+                                    imageUrl = "image URL",
+                                ),
+                                isFollowed = false
+                            )
+                        ),
+                        feed = emptyList()
+                    ),
+                    awaitItem()
+                )
+                cancel()
+            }
+    }
+
     @Test
     fun newsResourceSelectionUpdatesAfterLoadingFollowedTopics() = runTest {
         viewModel.uiState