Fix multiline login button text appearance.
Fix multiline login button text appearance.

Change-Id: Ia0109ac9c226a64f74dc827ed7a1646713a65c09

dbrant/apps-android-wikipedia,dbrant/apps-android-wikipedia,wikimedia/apps-android-wikipedia,wikimedia/apps-android-wikipedia,dbrant/apps-android-wikipedia,dbrant/apps-android-wikipedia,wikimedia/apps-android-wikipedia,dbrant/apps-android-wikipedia,wikimedia/apps-android-wikipedia