google_battery: add debug sysfs to fake cell fault detection status

  -- add a debug sysfs to fake single battery disconnect
     - /d/bpst/bpst_sbd_status
  -- TODO: to finish the implementation when the detection
           algorithm in b/203019566 lockdown

Bug: 203019566
Signed-off-by: Jack Wu <[email protected]>
Change-Id: I137b279ac5d73588b71f3772828df3498e3f60eb
1 file changed