Hide shadow overlay for contact tiles with letter tile avatars

Also tweak layout of letter tiles to better match redlines

Bug: 13101785
Change-Id: I1846947a389bbdccc30bfe388b24e80e8724a357
(cherry picked from commit 7846f2e0ed4def3202029f6ef5d6e0b350de0986)
dialer: Fix all_contacts button not being attached

When the dialer has no favorites settings the param of the parent of the favorites listview
caused all_contacts button is not being attached to the listview, and doesn't received events.

Change-Id: I0cf83b4ea4b3b3392898ed088ec11b3e706d86ca
Signed-off-by: Jorge Ruesga <jorge@ruesga.com>