Remove config_lowRamTaskSnapshotsAndRecents

config_lowRamTaskSnapshotsAndRecents was added to support icon recents.
The config scales recents to 0.1, and replaces the snapshot starting
window with the icon splash starting window when app is launched from
recents overview.

Bug: 144798942
Test: Check that wembley uses 0.6 snapshot scale, and that it uses
      snapshot for app transitions
Change-Id: I056fe0d194d1542c8ed251b946ab1aae99045d19