flo: Set BPF support level

This allows a legacy device launched with Android (pre-)O and running
a pre-4.9-P+ kernel to declare itself as not eBPF capable.

rootdir/etc/init.flo.rc

@@ -34,6 +34,8 @@ on init
     symlink /sdcard /mnt/sdcard
     symlink /sdcard /storage/sdcard0
 
+    setprop ro.kernel.ebpf.supported false
+
 on fs
     mount_all fstab.flo --early
     restorecon_recursive /persist