fix: use high resolution adaptive icons (#675)

Use high-resolution icons instead of the low-resolution ones on ReVanced Manager.

Commits:
* High resolution adaptive icons, built using revanced-logo-no-background.svg

Same icons currently used for ReVanced YouTube.

* tweak background color to match revanced-logo-no-background.svg

* recreated foreground using 'revanced-logo-shape.svg'

* updated full resolution icons, using same ratio as original SVG

* updated icons with gradient border

android/app/src/main/res/mipmap-anydpi-v26/ic_launcher.xml

@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="utf-8"?>
 <adaptive-icon xmlns:android="http://schemas.android.com/apk/res/android">
-  <background android:drawable="@color/ic_launcher_background"/>
+  <background android:drawable="@drawable/ic_launcher_background"/>
   <foreground android:drawable="@drawable/ic_launcher_foreground"/>
   <monochrome android:drawable="@drawable/ic_launcher_foreground"/>
 </adaptive-icon>

android/app/src/main/res/values/colors.xml

@@ -1,4 +0,0 @@
-<?xml version="1.0" encoding="utf-8"?>
-<resources>
-    <color name="ic_launcher_background">#1B1B1B</color>
-</resources>