[mob][photos] On applying the first filter on hierarchical search, add the initial gallery filter to applied filters

If we are on an album named 'Trip to Coorg' and another album filter is added, a functional  filter chip will get added to applied filters automatically

mobile/lib/ui/viewer/gallery/state/search_filter_data_provider.dart

@@ -8,6 +8,7 @@ class SearchFilterDataProvider {
   //TODO: Make this non-nullable and required so every time this is wrapped
   //over a gallery's scaffold, it's forced to provide an initial gallery filter
   HierarchicalSearchFilter? initialGalleryFilter;
+  bool _isSearching = false;
 
   List<HierarchicalSearchFilter> get recommendations =>
       _recommendedFiltersNotifier.recommendedFilters;
@@ -22,7 +23,12 @@ class SearchFilterDataProvider {
   }
 
   void applyFilters(List<HierarchicalSearchFilter> filters) {
-    _appliedFiltersNotifier.addFilters(filters);
+    if (!_isSearching) {
+      _isSearching = true;
+      _appliedFiltersNotifier.addFilters([initialGalleryFilter!, ...filters]);
+    } else {
+      _appliedFiltersNotifier.addFilters(filters);
+    }
     _recommendedFiltersNotifier.removeFilters(filters);
   }