Implement edge long swipe gesture

Author: Nico <nicorg2529@gmail.com>
Date:   Sun Mar 8 11:39:47 2020 +0000

    Implement edge long swipe gesture [1/3]

    The gesture will activate if user executes edge swipe for a long
    horizontal motion. The triggered action is configurable in Button
    Settings.

    Reference:
    https://gerrit.dirtyunicorns.com/q/topic:%22back-longswipe-actions%22

    Change-Id: Ie1bbe6645b6a00d346af60d6bb5e4d584997d6e9

Author: LuK1337 <priv.luk@gmail.com>
Date:   Thu Nov 25 17:39:29 2021 +0100

    Use custom flag for edge long swipe gesture

    Previously we were using same flags that'd be used for regular back key
    long press thus being unable to determine whether the event was sent
    from EdgeBackGestureHandle or not.

    Fixes: https://gitlab.com/LineageOS/issues/android/-/issues/4194
    Change-Id: I5c4fd455f581ac5c9c5e3a146095be33e82e8d6e

Change-Id: Iad2252081bc89e82ac70600e4178b0cb3a7f86c5