[BUG] (nightly) Blur Wallpaper Setting Is Not Dynamic

[D-Maxwell]

Describe the bug

hello there ;

as requested in #5125, the freshly implemented experimental "blur wallpaper" setting, although functional --on all devices, seemingly, mediatek users rejoice-- is applied on a global basis, effectively replacing the wallpaper as a whole, opposite to the original feature request.

Steps to reproduce

enable "blur wallpaper" experimental setting

Expected behavior

akin to its implementation in v2, and according to the aforementioned feature request, the blurred wallpaper should act as background material for specific components --i.e. the dock or app drawer-- blitted on top of the unblurred wallpaper, yet before any superimposed elements are drawn.

another way to see this is that components act as if they blurred elements underneath them down to the wallpaper, "in real time", if you will ; except that, since such a configuration of superimposed elements does not, and should not happen ; and that even if it were to, for the sake of both performance and aesthetics, a region of the preprocessed blurred wallpaper --with respect to already implemented user values-- should be blitted so as to overwrite anything (potentially) below, thereby ensuring legibility.

Screenshots

No response

Device information

• Device: Wiko View3 (Mediatek)
• OS: Android 9 stock (AOSP-ish, minor vendor tweaks)
• App version: 15.Dev (#2026)

Additional context

No response