Replace ProgressDialog with ProgressBar

[madhurgupta10]

Summary:
As per the discussion on the thread

We should replace the ProgressDialog with ProgressBar because it was deprecated in API 26
https://developer.android.com/reference/android/app/ProgressDialog

[Rishavgupta12345]

@nicolas-raoul i want to work on this issue please assign me

[Rishavgupta12345]

@madhurgupta10 @nicolas-raoul I was assigned this issue but I found out that this issue is pretty old.

and this feature is already implemented in our app, we are already using the progress bar in the ZOOM ACTIVITY.

so you can close this issue

[nicolas-raoul]

@Rishavgupta12345 : Understood, you are always free to unassign yourself from any issue. About closing this issue: I see that many classes are still using android.app.ProgressDialog, for instance fr/free/nrw/commons/upload/UploadActivity.java or fr/free/nrw/commons/auth/LoginActivity.java.