Do not always reset the filter

Author: astonbitecode

App/src/main/java/org/astonbitecode/rustkeylock/fragments/ShowEntry.java

@@ -259,7 +259,7 @@ private void prepareUiElements(View v) {
     @Override
     public void onBackButton() {
         Log.d(TAG, "Back button pressed");
-        InterfaceWithRust.INSTANCE.go_to_menu(JavaMenu.EntriesList(""));
+        InterfaceWithRust.INSTANCE.go_to_menu(JavaMenu.EntriesList(null));
     }
 
     @Override

rust/src/japi.rs

@@ -255,7 +255,7 @@ pub(crate) enum JavaMenu {
     TryPass { b: bool },
     ChangePass,
     Main,
-    EntriesList { filter: String },
+    EntriesList { filter: Option<String> },
     NewEntry,
     ShowEntry { idx: usize },
     EditEntry { idx: usize },