Update logic on when raw contact picker dialog is shown

Shouldn't be based on count of raw contacts, but whether writable
raw contacts exist.

Test:
Edit me profile that has 2 G+ accounts linked (where the me profile
has not already been created)
Edit an aggregate composed of 2 read-only accounts.
Edit aggregate of 1 write 1 read
Edit 1 read-only
Edit 1 write

Bug: 32289543
Bug: 31826229
Bug: 31088704
Change-Id: Ib01445b59fa9fc882a6d32d24f39917d726e6174