Settings: Fix bluetooth phone icon disappear in Settings/Bluetooth.

The ic_bt_cellphone icon color in ldrtl folder is white, it cannot be seen
in white background.

Modify ic_bt_cellphone icon color to green to be consistent with the icon
color in normal folder.

CRs-Fixed: 953015

Change-Id: I16ee4a7d485f594e817623fa4699c9e332d28e61