Fix ExternalStorageProvider always throw exception when rename

ExternalStorageProvider always throw exception when renameDocument
because it will check file exist when getFileForDocId. However,
beforeVisibleFile is not exist after rename, it will throw
exception. Fix it by put getting beforeVisibleFile before rename.

Test: manual test rename in DocumentsUI
Test: atest RenameActualProviderUiTest
Fix: 113302685
Fix: 115304092
Change-Id: I45d60d2f940e3dbc2b121f7cd28acc3c2d085ec4