refactor: avoid checking fragment is currentSelectedPosition is out of bounds

Author: rohit9625

app/src/main/java/fr/free/nrw/commons/upload/UploadActivity.kt

@@ -388,7 +388,10 @@ class UploadActivity : BaseActivity(), UploadContract.View, UploadBaseFragment.C
         fragments!!.removeAt(index) //Remove the corresponding fragment
         uploadableFiles.removeAt(index) //Remove the files from the list
 
-        if(fragments!![currentSelectedPosition] !is UploadMediaDetailFragment) {
+        val isMediaDetailFragment = fragments!!.getOrNull(currentSelectedPosition)?.let {
+            it is UploadMediaDetailFragment
+        } ?: false
+        if(!isMediaDetailFragment) {
             // Should hide the top card current fragment is not the media detail fragment
             showHideTopCard(false)
         }