chore(android): update companion apk download

Render the full circular badge (bright grey->white ring + grid) to round-icon
PNGs at all densities and drop the adaptive round XML, so launchers that use
round icons show a real edge-to-edge circle instead of a mask-cropped coin.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Android/app/src/main/res/mipmap-anydpi-v26/ic_launcher_round.xml

@@ -1,5 +0,0 @@
-<?xml version="1.0" encoding="utf-8"?>
-<adaptive-icon xmlns:android="http://schemas.android.com/apk/res/android">
-    <background android:drawable="@drawable/ic_launcher_background" />
-    <foreground android:drawable="@drawable/ic_launcher_foreground" />
-</adaptive-icon>