Lockscreen shortcuts
Lockscreen shortcuts: delete entry if reset

Delete the entry when resetAll is selected so that original AOSP
behaviour is present, such as magneticTargets.
Lockscreen shortcuts Icon Revamp

Adjust the size of custom app icons and resize and round the corners
of gallery icons for a more uniform look.

Change-Id: I75f3656ae5b4ac4a4bd1c1cbed6c07ab2863f4fd
Quick launch shortcuts
Lockscreen targets: added contact lockscreen icon
Lockscreen targets: replace talk with hangouts
Lockscreen shortcuts: fix empty magnetic behaviour

When no valid targets are set, set settings to null in order
to enable magnetic targets (aosp behavior)
Fix adding apps to lockscreen targets without explicit icon selection.