Add overlap handling to redirect_fds(). am: c718268549 am: b4848039ee am: 4b324e8442 am: 82c0f84acd

Original change: https://android-review.googlesource.com/c/platform/external/minijail/+/1675393

Change-Id: I77012112c5d356da9af81cfca4291eb28dfd46d5