Lockscreen Torch: Add Volume Up and Down Keys

we also change lockscreen volume disable to Highest priority which
would be run the latest in an after hook

High.before > Normal.before > Low.before > Actual method
>Low.after>normal.after>high.after

The lockscreen torch would then be normal priority and ren BEFORE
lockscreen volume disable which allows the torch to be activated before
it reaches the disable (which is what we want)
Cleanup: Ctrl+Shift+F in pref_setting.xml

(no changes to the code at all, only the tabs and lines )