[Ongoing Call Chip] Don't show the chip on lockscreen.

Also moves the #initNotificationIconArea call to be within
CollapsedStatusBarFragment, rather than requiring StatusBar to call it.
This makes our unit tests better because now we don't need to call it
manually.

Also fix a bug in #onDozingChanged that was passing disabled1 in for
disabled2.

Test: atest and manual
Bug: 183229367
Fixes: 185897059
Change-Id: I0a65f9e90e66680f0b602b89f89ec0a4900e9df8