style(icon): Update icon to Material Symbol variant

Signed-off-by: Andy Scherzinger <info@andy-scherzinger.de>

app/src/main/res/drawable/ic_external.xml

@@ -1,16 +1,15 @@
 <!--
   ~ Nextcloud - Android Client
   ~
-  ~ SPDX-FileCopyrightText: 2019-2024 Nextcloud GmbH
-  ~ SPDX-FileCopyrightText: 2019-2024 Tobias Kaminsky <tobias@kaminsky.me>
-  ~ SPDX-License-Identifier: AGPL-3.0-or-later OR GPL-2.0-only
+  ~ SPDX-FileCopyrightText: 2018-2024 Google LLC
+  ~ SPDX-License-Identifier: Apache-2.0
 -->
 <vector xmlns:android="http://schemas.android.com/apk/res/android"
     android:width="24dp"
     android:height="24dp"
-    android:viewportWidth="16"
-    android:viewportHeight="16">
+    android:viewportWidth="960"
+    android:viewportHeight="960">
     <path
         android:fillColor="#FF000000"
-        android:pathData="M7.452,1.62l2.38,2.256 -3.57,3.386L8.64,9.52l3.57,-3.387 2.38,2.257V1.618h-7.14zM2.69,2.746c-0.66,0 -1.19,0.504 -1.19,1.13v9.028c0,0.625 0.53,1.128 1.19,1.128h9.522c0.66,0 1.19,-0.503 1.19,-1.128V9.52l-1.19,-1.13v4.515h-9.52v-9.03h4.76l-1.19,-1.128H2.69z" />
+        android:pathData="M200,840q-33,0 -56.5,-23.5T120,760v-560q0,-33 23.5,-56.5T200,120h280v80L200,200v560h560v-280h80v280q0,33 -23.5,56.5T760,840L200,840ZM388,628 L332,572 704,200L560,200v-80h280v280h-80v-144L388,628Z" />
 </vector>