Well i think i finally found a very handy app to disable the Reply with Message option on XPERIA phones.
Although this app does not disables that option but changes the Incoming call screen of the XPERIA phone. I am using it now in my XPERIA Z1 C...
I dont want to unlock bootloader or flash
Check out this for Solution.,., its working for me superbly
any can update the link,,.,!!
the following 2 are not working.. .. . at the moment
super coool man.,., working on Xpreia S, 4.1.2, 0.211 ,.,..