Use animateItemPlacement() on feed

Change-Id: Id120a6e84e0641679fa54ebf0e34bb04165aa419

core/ui/src/main/kotlin/com/google/samples/apps/nowinandroid/core/ui/NewsFeed.kt

@@ -21,6 +21,7 @@ import android.net.Uri
 import androidx.annotation.ColorInt
 import androidx.browser.customtabs.CustomTabColorSchemeParams
 import androidx.browser.customtabs.CustomTabsIntent
+import androidx.compose.foundation.ExperimentalFoundationApi
 import androidx.compose.foundation.layout.padding
 import androidx.compose.foundation.lazy.LazyListScope
 import androidx.compose.foundation.lazy.staggeredgrid.LazyStaggeredGridScope
@@ -47,6 +48,7 @@ import com.google.samples.apps.nowinandroid.core.model.data.UserNewsResource
  * An extension on [LazyListScope] defining a feed with news resources.
  * Depending on the [feedState], this might emit no items.
  */
+@OptIn(ExperimentalFoundationApi::class)
 fun LazyStaggeredGridScope.newsFeed(
     feedState: NewsFeedUiState,
     onNewsResourcesCheckedChanged: (String, Boolean) -> Unit,
@@ -88,7 +90,9 @@ fun LazyStaggeredGridScope.newsFeed(
                         )
                     },
                     onTopicClick = onTopicClick,
-                    modifier = Modifier.padding(horizontal = 8.dp),
+                    modifier = Modifier
+                        .padding(horizontal = 8.dp)
+                        .animateItemPlacement(),
                 )
             }
         }