init.rc: Remount / with MS_REMOUNT|MS_BIND|MS_NODEV

/ should not have any character/block devices, so might as well pass in
the nodev flag.

Bug: 73255020
Test: aosp_sailfish still boots
Test: sailfish:/ # find / -xdev -a \( -type b -o -type c -o -type p -o -type s \)
      sailfish:/ #
Test: rootfs on / type rootfs (rw,seclabel)
      /dev/root on / type ext4 (ro,seclabel,nodevrelatime)

Change-Id: Ia73e04b53a47506892d9d3cb61b471b81bb72dc3