Revert "Bug 971654 - Correct lockscreen background sizing"

This reverts commit 21d0c2d77314325e7330daf4ebb90ed844a0c9ed.
Merge pull request #16609 from EverythingMe/bug-975917

Bug 975917 - [Everything.me] Tapping homebutton while in Collection Rena...
Bug 976546 - User should not be able to pull down utility tray before unlock
Bug 975971 - [keyboard refactor] Convert input_field.js to instantiable pattern
Bug 975971 (part 2) - [keyboard refactor] Convert shiftkey.js to instantiable pattern
Bug 975971 (part 3) - [keyboard refactor] Convert autocorrect.js to instantiable pattern
Add display:flex for fix height 100% on iframe
Merge pull request #16184 from pivanov/bug-950147

Bug 950147 - Add new Illustrative Wallpapers for v.1.4
Bug 965302 - [Feedback] clean up HTML r=kgrandon
Merge pull request #16661 from KevinGrandon/ZDroid-html5fact

Bug 965302 - [Feedback] clean up HTML r=kgrandon
Bug 977039 - [email] remove obsolete string entity setup-info-header
Bug 976174 - Better failure message in switch_to_keyboard() and dismiss()
Merge pull request #16653 from KevinGrandon/bug_976546_utility_tray_shown

Bug 976546 - User should not be able to pull down utility tray before unlock
Bug 976063 - Python - make wait_*_not run faster
Merge pull request #16068 from flodolo/bug932270_ampm

Bug 932270 - Make AM/PM localizable in 12 hours format
Merge pull request #16620 from zacc/bug_976174

Bug 976174 - Better failure message in switch_to_keyboard() and dismiss(...
Merge pull request #16615 from eeejay/bug-976215

Bug 976215 - [System] Make utility tray invisible. r=21
Bug 976684 - [Settings] Fix typo in screen reader start button label. r=kaze
Merge pull request #16632 from eeejay/bug-976684

Bug 976684 - [Settings] Fix typo in screen reader start button label.
intermittent in test_settings_from_message