Framwork: Add support for variable size pattern lockscreen (Part 1/2)

Changes LockPatternView to use PATTERN_SIZE instead of the hardcoded value '3'.
Adds methods to set and get PATTERN_SIZE via LockPatternUtils and device settings.

With this patch the pattern lockscreen can go from 3x3 to any sane size such as 6x6.
LockPatternView can be taken by itself if settings are not desired, for an easy way to change the hardcoded size.

Patch Set 3: Rebased,
should fix cherry-pick after the "widgets before unlock" commit.

Patch Set 4+5: Fix whitespace
Patch Set 6: Missed one Gremlin. (Fixed for real)

Patch Set 7: Rebased

Patch Set 8: Added missing hide statements

Change-Id: Ibc0d5bfcee9673b1bf049bd69be80d2312602a47