vivo 手机获取 BUCKET_DISPLAY_NAME 为空，版本号 2.5.8

Process Name: 'com.mockuai.mkselleros'
Thread Name: 'main'
Back traces starts.
java.lang.NullPointerException: Attempt to invoke virtual method 'boolean java.lang.String.startsWith(java.lang.String)' on a null object reference
at com.luck.picture.lib.PictureSelectorActivity.manualSaveFolderForPageModel(PictureSelectorActivity.java:2009)
at com.luck.picture.lib.PictureSelectorActivity.notifyAdapterData(PictureSelectorActivity.java:1683)
at com.luck.picture.lib.PictureSelectorActivity.access$200(PictureSelectorActivity.java:80)
at com.luck.picture.lib.PictureSelectorActivity.access$100(PictureSelectorActivity.java:80)
at com.luck.picture.lib.PictureSelectorActivity.onPictureClick(PictureSelectorActivity.java:80)
at com.luck.picture.lib.PictureSelectorActivity.access$000(PictureSelectorActivity.java:80)
at com.luck.picture.lib.PictureSelectorActivity$5.onSuccess(PictureSelectorActivity.java:1647)
at com.luck.picture.lib.PictureSelectorActivity$5.onSuccess(PictureSelectorActivity.java:1572)
at com.luck.picture.lib.thread.PictureThreadUtils$Task$2.run(PictureThreadUtils.java:1207)
at android.os.Handler.handleCallback(Handler.java:938)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loop(Looper.java:257)
at android.app.ActivityThread.main(ActivityThread.java:8178)
at java.lang.reflect.Method.invoke(Method.java)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:626)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1015)
Back traces ends.

设备型号：V2046A

Start in PictureSelectorActivity.java at manualSaveFolderForPageModel, line 2009, following the call from notifyAdapterData. Investigate the vivo V2046A case where BUCKET_DISPLAY_NAME is empty and identify the null value behind the startsWith failure. Reproduce or add coverage for this path, then verify that selecting a picture no longer crashes.

Written by the indexing model from the issue text.