[shade] marquee the battery remaining text if need be

Test: manual; `adb shell cmd battery unplug` and verify that the text
marquees only when font size is set to max
Fixes: 409157513
Flag: com.android.settingslib.flags.new_status_bar_icons
Flag: com.android.systemui.status_bar_root_modernization

Change-Id: I92e05c04993398faf84c42215d1fbaae9f8282a8