App header cleanup

App header cleanup

- Refactor the entity header layout to use LinearLayout and add id to
  content area
- Remove now unused AppHeader class
- Make entire icon+text area clickable and link to app info page
  Refactor the binding logic from bindButton to its own method.
- Remove unused MultiLinePreference

Fix: 62705377
Test: make RunSettingsRoboTests

Change-Id: I6db554695410e71b669f6fdba29d98fedc3364b9