[1/2] Add lockscreen rotation as an optional rotation setting

Taken fom Omni: https://gerrit.omnirom.org/6441
Who takes it from: https://github.com/gokussjx/cm_packages_apps_Settings/commit/a83ae47e184a778ca3067416c56901da70c1bc27

PS2: fix value handling; make option stick
PS3: fix derp, re-add missing symbol
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PS7: Fix the checkbox.
PS8: Fix a little derp.

Change-Id: I3fd1d2c31d83230d480a0027cb7bf5fcf2db5cb7
Merge "[1/2] Add lockscreen rotation as an optional rotation setting" into pac-4.4