AndroidManifest: don't request WRITE_EXTERNAL_STORAGE above api 29

Signed-off-by: Álvaro Brey Vilas <alvaro.brey@nextcloud.com>

src/main/AndroidManifest.xml

@@ -51,7 +51,10 @@
 
     <!-- WRITE_EXTERNAL_STORAGE may be enabled or disabled by the user after installation in
         API >= 23; the app needs to handle this -->
-    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
+    <uses-permission
+        android:name="android.permission.WRITE_EXTERNAL_STORAGE"
+        android:maxSdkVersion="29"
+        tools:ignore="ScopedStorage" />
     <uses-permission android:name="android.permission.CAMERA" />
     <uses-permission android:name="android.permission.VIBRATE" />