Fix the "No service" text being too far away from the status icons

The issue was that the "No service" View was a minimum width. If the
text inside of it is smaller than the minimum width, there will be an
empty space after the text to fill the minimum width, and make it look
like the View is far away from the status icons.

The fix here is to set the gravity to Gravity.END, so that the text is
aligned to be closest to the status icons.

Test: Connect an external display and pull down the shade on the
      external display.
Fixes: 437081075
Flag: com.android.systemui.fix_shade_header_wrong_icon_size
Change-Id: Icb76afeac82794f04f50ebe790b89c15643cb722