Show/Hide lockscreen camera and searchlight buttons (1 of 2)

Change-Id: I22fc4abeb11b8cfa6a91a891ea4e286ebb58f0d3
Adapt softkey action handling from @vaniraosp and @AlmightyMegadeth00 (1 of 2)

This adaptation required minor adjustments in KBV for Eos ActionHandler
framework. Also, it became obvious we need a "SoftkeyActionHandler" class
similar to the NxActionHandler.

PS2: Introduce SoftkeyActionHandler extends ActionHandler
     Manages action state of soft keys, and dispatches
     actions

PS3: framework for configurable long press and double tap timeout

PS4: Default AOSP Tap timeout configuration

PS5: Actually observe the longpress timeout uri, it helps

PS6: Fix bringup and observer for real

PS7: Propagate mIsRecreating

Change-Id: I12db73ac6f5bcef508973180be7faf4d630736a9
Persistent menu soft key (1 of 2)

Shows all the time, except in lockscreen

Change-Id: I44048f16112dea7f31f2e4ecd3565ebbe1a53cee