UX updates to read-only view of raw contact

Use back arrow for navigation icon.
Use "view only" string for title.
Change account header per screenshot in bug.

Test:
Manually checked and verified headers/navigation icons/titles of:
  * view of read-only raw contact
  * edit view of writable raw contact
  * add new contact

Bug: 31868376
Change-Id: I1d390f785bf4c0de90102e6a9e02477a8c19ddee