Lockscreen: See through (1/2)

Add the ability to see through lockscreen.
Adapted to kitkat from jellybean by @BigBrother1984

Signed-off-by: D4rKn3sSyS <jesdga95@gmail.com>
Signed-off-by: Carlo Savignano <stevewatersy@gmail.com>

PS2:

* Adding missing sem-colon.

Signed-off-by: Carlo Savignano <stevewatersy@gmail.com>

Change-Id: I9057a6e302a5a824799844f27e8f64ff677a520a

PS3:

* Replace and remove undefined mContext.
* Define the boolean enableScreenRotation inside new method.
* Whitespaces clean up.

Signed-off-by: Carlo Savignano <stevewatersy@gmail.com>

PS4:

* Restore mContext in setKeyguardParams().

Signed-off-by: Carlo Savignano <stevewatersy@gmail.com>

PS5:

* Fixes for setKeyguardParams() and maybeCreateKeyguardLocked() methods, kitkat changed some things.

Signed-off-by: Carlo Savignano <stevewatersy@gmail.com>

PS6:

* Missing sem-colon.

Signed-off-by: Carlo Savignano <stevewatersy@gmail.com>

PS7: Fix all the things.

* Effects doesn't vanish after first unlock.
* Created condition in updateShowWallpaper() method that just return if see through is activated, he was restoring the wallpaper at second lock.

Signed-off-by: Carlo Savignano <stevewatersy@gmail.com>

PS8: Cosmetic changes.

* Correct java style name to seeThrough() and place it above updateShowWallpaper().

Signed-off-by: Carlo Savignano <stevewatersy@gmail.com>

PS9: Other cosmetic changes.

* Better name to the see through boolean.
* Removed a space nitpick.

Signed-off-by: Carlo Savignano <stevewatersy@gmail.com>

PS10:

* We had two booleans for the same thing, ditch the one defined in one class only and take the global.

Signed-off-by: Carlo Savignano <stevewatersy@gmail.com>

Conflicts:
	core/java/android/provider/Settings.java
Fix: Ensure lockscreen see through setting persists after reboot

If see through was enabled and the device was rebooted,
the user had to toggle the setting off and on again to activate.

Change-Id: Id3d6942dd39fe95ec3a8aec6d27ff85642ae7632
Fix: Correct possible null pointer when enabling see through lockscreen

Change-Id: Iee3b51504a1d233c63ef9d4a97f9cf4d51f42694
PS2: Remove unused variable