App crash because of a leak when searching for cities

[matrujillo10]

Hi,

I found a bug when I tried to search for a new city and then rotate the phone.

2019-11-23 23:36:12.090 27466-27466/com.haringeymobile.ukweather E/WindowManager: android.view.WindowLeaked: Activity com.haringeymobile.ukweather.MainActivity has leaked window DecorView@b58997[] that was originally added here
        at android.view.ViewRootImpl.<init>(ViewRootImpl.java:485)
        at android.view.WindowManagerGlobal.addView(WindowManagerGlobal.java:346)
        at android.view.WindowManagerImpl.addView(WindowManagerImpl.java:92)
        at android.app.Dialog.show(Dialog.java:330)
        at com.haringeymobile.ukweather.utils.AsyncTaskWithProgressBar.onPreExecute(AsyncTaskWithProgressBar.java:45)
        at android.os.AsyncTask.executeOnExecutor(AsyncTask.java:648)
        at android.os.AsyncTask.execute(AsyncTask.java:595)
        at com.haringeymobile.ukweather.MainActivity.onQueryTextSubmit(MainActivity.java:256)
        at com.haringeymobile.ukweather.AddCityFragment.onNewCityQuerySubmitted(AddCityFragment.java:96)
        at com.haringeymobile.ukweather.AddCityFragment.access$000(AddCityFragment.java:20)
        at com.haringeymobile.ukweather.AddCityFragment$1.onClick(AddCityFragment.java:74)
        at android.view.View.performClick(View.java:6256)
        at android.view.View$PerformClick.run(View.java:24701)
        at android.os.Handler.handleCallback(Handler.java:789)
        at android.os.Handler.dispatchMessage(Handler.java:98)
        at android.os.Looper.loop(Looper.java:164)
        at android.app.ActivityThread.main(ActivityThread.java:6541)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.Zygote$MethodAndArgsCaller.run(Zygote.java:240)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:767)
2019-11-23 23:36:13.928 27466-27466/com.haringeymobile.ukweather E/AndroidRuntime: FATAL EXCEPTION: main
    Process: com.haringeymobile.ukweather, PID: 27466
    java.lang.IllegalArgumentException: View=DecorView@b58997[] not attached to window manager
        at android.view.WindowManagerGlobal.findViewLocked(WindowManagerGlobal.java:485)
        at android.view.WindowManagerGlobal.removeView(WindowManagerGlobal.java:394)
        at android.view.WindowManagerImpl.removeViewImmediate(WindowManagerImpl.java:123)
        at android.app.Dialog.dismissDialog(Dialog.java:371)
        at android.app.Dialog.dismiss(Dialog.java:354)
        at com.haringeymobile.ukweather.utils.AsyncTaskWithProgressBar.onPostExecute(AsyncTaskWithProgressBar.java:61)
        at com.haringeymobile.ukweather.GetAvailableCitiesTask.onPostExecute(GetAvailableCitiesTask.java:71)
        at com.haringeymobile.ukweather.GetAvailableCitiesTask.onPostExecute(GetAvailableCitiesTask.java:24)
        at android.os.AsyncTask.finish(AsyncTask.java:695)
        at android.os.AsyncTask.-wrap1(Unknown Source:0)
        at android.os.AsyncTask$InternalHandler.handleMessage(AsyncTask.java:712)
        at android.os.Handler.dispatchMessage(Handler.java:105)
        at android.os.Looper.loop(Looper.java:164)
        at android.app.ActivityThread.main(ActivityThread.java:6541)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.Zygote$MethodAndArgsCaller.run(Zygote.java:240)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:767)

I made a flow diagram for replicate the bug: