[BUGFIX] Set default permissions for new files to 0664

Change-Id: I4c71414dca763d9ba29ab93b18a0389941f51af7
Resolves: #58809
Releases: 6.2
Reviewed-on: https://review.typo3.org/30113
Reviewed-by: Dmitry Dulepov
Reviewed-by: Oliver Klee
Reviewed-by: Markus Klein
Tested-by: Markus Klein