问题背景
当设备无法成功解析EONS(PNN)的值（即SIM卡EF文件内容），则会用次优先级的NITZ去refresh了SPN。（问题代码如下，是通过Phone对象拿到plmn为空）
运营商名称一般显示优先级：Eons > NITZ > XML
OPL id 0 对应的是PNN第一条
功能逻辑
（定制）当卡中的spn为空，会用PLMN的值更新SPN的值，即SPN = PLMN
DUT:
04-26 12:55:59.687011 2013 2013 D OPCDNR : CarrierName from EF: { spn = AT&T...1, dataSpn = null, showSpn = true, plmn = AT&T...1, showPlmn = false
04-26 12:55:59.692141 2013 2013 D OPServiceStateTracker: [0] updateSpnDisplayCdnr-
04-26 12:56:01.475726 2013 2013 D MTKSST : [GsmSST0] refreshSpn: AT&T...1, AT&T...1, fromPollState=true, needPollState=false
04-26 12:56:01.494990 2013 2013 D OPServiceStateTracker: [0] updateSpnDisplayCdnr+
04-26 12:56:01.495963 2013 2013 D OPServiceStateTracker: [0] updateSpnDisplayCdnr: curSpn = null; curPlmn = AT&T...1; curDisplayRule = 0
Android T 代码
frameworks/opt/telephony/src/java/
