Reduce legacy lockscreen bottom area on small land screens - follow-up

Follow-up to ag/24745109
- added additional flag guarding
- added line (128) missed in ag/24745109
- indication area moved downwards (reduced margins)

This is a required feature for landscape lockscreen for small screens

Guarded by flag "lockscreen.enable_landscape" (b/293252410)

Bug: 296571001
Bug: 293252410

Test: LockIconViewControllerTest
Change-Id: Ib07e0084bb00e94b723f82505a605aca74574be7