Correct the lockscreen carrier text alignment and text color

In AOSP the text is left aligned, not centered, and the text color is white, not grey

Change-Id: Ie9c77761d3440336ae57abed24c8403bda06be3e
Merge branch 'cm-12.0' of https://www.github.com/cyanogenmod/android_frameworks_base into cm-12.0