deb: Use sys.io.scheduler for 12

Take logic from lineage-iosched.rc

As "prebuilt/common/etc/init/lineage-iosched.rc" has been removed
be135083d6

rootdir/etc/init.deb.rc

@@ -138,6 +138,22 @@ on boot
 
     chown wifi wifi /sys/module/wlan/parameters/fwpath
 
+    restorecon --recursive /sys/block/mmcblk0/queue
+    chown system system /sys/block/mmcblk0/queue/scheduler
+    chmod 0664 /sys/block/mmcblk0/queue/scheduler
+
+# Configure IO scheduler
+on property:sys.io.scheduler=*
+    write /sys/block/mmcblk0/queue/scheduler ${sys.io.scheduler}
+
+on property:persist.sys.io.scheduler=*
+    setprop sys.io.scheduler ${persist.sys.io.scheduler}
+
+# Set slice_idle to 0 for CFQ
+on property:sys.io.scheduler=cfq
+    restorecon --recursive /sys/block/mmcblk0/queue
+    write /sys/block/mmcblk0/queue/iosched/slice_idle 0
+
 on property:sys.boot_completed=1
     setprop sys.io.scheduler cfq
     write /sys/block/mmcblk0/bdi/read_ahead_kb 256