Migrate to Material3 design.

Fixes #1586.

src/main/res/menu/list_context_menu.xml

@@ -35,11 +35,6 @@ limitations under the License.
         android:icon="@drawable/ic_delete_forever_24dp"
         android:title="@string/menu_delete"
         app:showAsAction="ifRoom" />
-    <item
-        android:id="@+id/list_context_menu_aggregated_stats"
-        android:icon="@drawable/ic_statistics_24dp"
-        android:title="@string/menu_aggregated_statistics"
-        app:showAsAction="ifRoom" />
     <item
         android:id="@+id/list_context_menu_select_all"
         android:icon="@drawable/ic_select_all_24dp"

src/main/res/menu/track_list.xml

@@ -15,18 +15,6 @@ limitations under the License.
 -->
 <menu xmlns:android="http://schemas.android.com/apk/res/android"
     xmlns:app="http://schemas.android.com/apk/res-auto">
-    <item
-        android:id="@+id/track_list_aggregated_stats"
-        android:icon="@drawable/ic_statistics_24dp"
-        android:title="@string/menu_aggregated_statistics"
-        app:showAsAction="ifRoom" />
-    <!-- Icon, title, and visibility is managed by TrackListActivity -->
-    <item
-        android:id="@+id/track_list_start_gps"
-        android:icon="@drawable/ic_gps_off_24dp"
-        android:title="@string/menu_start_gps"
-        android:visible="false"
-        app:showAsAction="ifRoom" />
     <!-- TODO SearchAction is only working if it is shown as action. However, only two slots are available. See  #757. -->
     <item
         android:id="@+id/track_list_search"
@@ -44,6 +32,7 @@ limitations under the License.
         android:title="@string/menu_settings" />
     <item
         android:id="@+id/track_list_help"
+        android:icon="@drawable/ic_help_black_24dp"
         android:title="@string/menu_help" />
 
 </menu>