Merge "Remove volume plus flag in Settings" into main

aconfig/settings_panel_flag_declarations.aconfig

@@ -1,9 +0,0 @@
-package: "com.android.settings.flags"
-container: "system"
-
-flag {
-  name: "enable_volume_plus_quick_settings"
-  namespace: "pixel_cross_device_control"
-  description: "Gates whether to enable VolumePlus quick settings panel."
-  bug: "309052662"
-}