Fixes ApnEditor not restoring previous UI

ApnEditor tries read and set the UI in onCreate, before the previous
bundle is restored. This caused problems when the configuration has
changed (such as switching to Dark Theme).

This moves the UI changes to onViewRestored

Fixes: 146399432
Test: make SettingsGoogle and manual test UI
Change-Id: I8147ec96569fa28867c088d6c36584aa344f40ed
Merged-In: I8147ec96569fa28867c088d6c36584aa344f40ed