android: Remove blocking permission request code. Async only in SDL3!

(this actually still blocks at our internal points of usage, though, for
replacement at a later time.)

src/dynapi/SDL_dynapi.sym

@@ -972,7 +972,6 @@ SDL3_0.0.0 {
     SDL_RenderGeometryRawFloat;
     SDL_SetWindowShape;
     SDL_RenderViewportSet;
-    SDL_AndroidRequestPermissionAsync;
     # extra symbols go here (don't modify this line)
   local: *;
 };