9/N Clean Up Keyguard Class Structure

KeyguardInputView no longer implements KeyguardSecurityView.

This cl seeks to clean up some of the lingering vestiges from this
large chain of refactors.

I have manually tested none, swipe, pattern, pin, and password views
for successfully unlocking, as well as multiple failed attempts
resulting in temporary lock outs.

Fixes: 166448040
Test: atest SystemUITests && manual
Change-Id: I36275598001184e774677cf2dbb16dec8dc7ab5b