for oracle use BITAND() instead of & in sharing permissions sql

@icewind1991 @DeepDiver1975 @MTGap oracle needs BITAND() instead of & in sql. If you have a better idea than the conditional, I'm all for it. No, the doctrine DBAL does not solve this problem.

Also, @Raydiation I saw a lot of occurrences of  & in SQL in the news app, would be awesome if you could add this fix to the news app as well.

quick shell command to search for possible occurences:
```sh
find . -name "*.php" -follow -exec grep " & " {} + | grep \` 
```