Rework the lockscreen blur (1/2)

Based off this, https://github.com/AOKP/frameworks_base/commit/317fc1f706fe3797d6362122dbe8b446f2563056

Change-Id: I111b025c862b37b8d72f39750d9402d255e70aa5
Signed-off-by: Lokesh Chamane <lokesh.c703@gmail.com>