FileDisplayActivity: Restore showFile function that was lost in the rebase

Signed-off-by: Álvaro Brey Vilas <alvaro.brey@nextcloud.com>

src/main/java/com/owncloud/android/ui/activity/FileDisplayActivity.java

@@ -2523,4 +2523,20 @@ public class FileDisplayActivity extends FileActivity
         transaction.addToBackStack(null);
         transaction.commit();
     }
+
+    public void showFile(String message) {
+        dismissLoadingDialog();
+
+        OCFileListFragment listOfFiles = getListOfFilesFragment();
+        if (listOfFiles != null) {
+            if (TextUtils.isEmpty(message)) {
+                OCFile temp = getFile();
+                setFile(getCurrentDir());
+                listOfFiles.listDirectory(getCurrentDir(), temp, MainApp.isOnlyOnDevice(), false);
+                updateActionBarTitleAndHomeButton(null);
+            } else {
+                DisplayUtils.showSnackMessage(listOfFiles.getView(), message);
+            }
+        }
+    }
 }

src/main/java/com/owncloud/android/ui/asynctasks/FetchRemoteFileTask.java

@@ -120,6 +120,6 @@ public class FetchRemoteFileTask extends AsyncTask<Void, Void, String> {
     protected void onPostExecute(String message) {
         super.onPostExecute(message);
 
-        fileDisplayActivity.showFiles(false);
+        fileDisplayActivity.showFile(message);
     }
 }

src/main/java/com/owncloud/android/ui/fragment/UnifiedSearchFragment.kt

@@ -123,7 +123,7 @@ class UnifiedSearchFragment : Fragment(), Injectable, UnifiedSearchListInterface
             if (activity is FileDisplayActivity) {
                 val fda = activity as FileDisplayActivity
                 fda.file = result.file
-                fda.showFiles(false)
+                fda.showFile("")
             }
         }
     }