fix Directory and media sorting

app/src/main/kotlin/com/simplemobiletools/gallery/activities/ViewPagerActivity.kt

@@ -385,7 +385,7 @@ class ViewPagerActivity : SimpleActivity(), ViewPager.OnPageChangeListener, View
 
         scanFiles(invalidFiles) {}
         Medium.sorting = mConfig.sorting
-        Collections.sort(media)
+        media.sort()
         var j = 0
         for (medium in media) {
             if (medium.path == mPath) {

app/src/main/kotlin/com/simplemobiletools/gallery/asynctasks/GetDirectoriesAsynctask.kt

@@ -76,7 +76,7 @@ class GetDirectoriesAsynctask(val context: Context, val isPickVideo: Boolean, va
         val dirs = ArrayList(directories.values)
         filterDirectories(dirs)
         Directory.sorting = mConfig.directorySorting
-        Collections.sort<Directory>(dirs)
+        dirs.sort()
 
         context.scanFiles(invalidFiles) {}
         return dirs

app/src/main/kotlin/com/simplemobiletools/gallery/models/Directory.kt

@@ -12,7 +12,7 @@ class Directory(val path: String, val thumbnail: String, val name: String, var m
     override fun compareTo(other: Directory): Int {
         var res: Int
         if (sorting and SORT_BY_NAME != 0) {
-            res = path.compareTo(other.path)
+            res = name.toLowerCase().compareTo(other.name.toLowerCase())
         } else if (sorting and SORT_BY_DATE != 0) {
             res = if (timestamp > other.timestamp) 1 else -1
         } else {

app/src/main/kotlin/com/simplemobiletools/gallery/models/Medium.kt

@@ -17,7 +17,7 @@ class Medium(val name: String, var path: String, val isVideo: Boolean, val times
     override fun compareTo(other: Medium): Int {
         var res: Int
         if (sorting and SORT_BY_NAME != 0) {
-            res = path.compareTo(other.path)
+            res = name.toLowerCase().compareTo(other.name.toLowerCase())
         } else if (sorting and SORT_BY_DATE != 0) {
             res = if (timestamp > other.timestamp) 1 else -1
         } else {