Our typical touchscreens are now good enough that we don't need the touch slop to be as large as it once was. Lower it to increase responsiveness while scrolling. Move the touch slop constant to the config resource config_viewConfigurationTouchSlop so that it may be more easily tweaked in device-specific overlays. Change-Id: I7c11d8affcb98e91654203beb13a26cfeec18f7c