squash pdf export + storage permissions

android/app/src/main/AndroidManifest.xml

@@ -1,6 +1,9 @@
 <manifest xmlns:android="http://schemas.android.com/apk/res/android"
     package="eu.heili.notes">
+    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
+    <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE"/>
    <application
+           android:requestLegacyExternalStorage="true"
         android:label="notes"
         android:name="${applicationName}"
         android:icon="@mipmap/ic_launcher">