limit the cached folders size to 60 just to be sure

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

@@ -602,7 +602,8 @@ class MainActivity : SimpleActivity(), DirectoryAdapter.DirOperationsListener {
 
     private fun storeDirectories() {
         if (!config.temporarilyShowHidden && config.tempFolderPath.isEmpty()) {
-            val directories = Gson().toJson(mDirs)
+            val subList = mDirs.subList(0, Math.min(SAVE_DIRS_CNT, mDirs.size))
+            val directories = Gson().toJson(subList)
             config.directories = directories
         }
     }

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

@@ -45,7 +45,6 @@ import java.io.File
 import java.io.IOException
 
 class MediaActivity : SimpleActivity(), MediaAdapter.MediaOperationsListener {
-    private val SAVE_MEDIA_CNT = 80
     private val LAST_MEDIA_CHECK_PERIOD = 3000L
 
     private var mPath = ""

app/src/main/kotlin/com/simplemobiletools/gallery/helpers/Constants.kt

@@ -65,6 +65,8 @@ const val MAX_COLUMN_COUNT = 20
 const val SHOW_TEMP_HIDDEN_DURATION = 600000L
 const val CLICK_MAX_DURATION = 150
 const val DRAG_THRESHOLD = 8
+const val SAVE_DIRS_CNT = 60
+const val SAVE_MEDIA_CNT = 80
 
 const val DIRECTORY = "directory"
 const val MEDIUM = "medium"