4/N Setup Controller fo KeyguardSecurityContainer.

Move the guts of KeyguardSecurityContainer into
KeyguardSecurityContainerController. This removes a lot of
Dependency#get calls, and is another step towards simplifying our
view inflation process.

CustomViews that previously implemented KeyguardSecurityView now
all extend KeyguardInputView, allowing them to be simultaneously
treated as one while also being recognized as a View (the interface
required a lot of casting back and forth to a View).

LockscreenUtil is made a Singleton in this CL.

Bug: 166448040
Test: atest SystemUITests && manual
Change-Id: I6fa05012c55f5e003ab551d2f8360891a62fa2a7