Export is a pro feature

app/src/main/java/eu/faircode/email/FragmentOptionsBackup.java

@@ -109,6 +109,7 @@ public class FragmentOptionsBackup extends FragmentBase implements SharedPrefere
     private View view;
     private ImageButton ibHelp;
     private Button btnExport;
+    private TextView tvExportPro;
     private Button btnImport;
     private CardView cardCloud;
     private TextView tvCloudInfo;
@@ -151,6 +152,7 @@ public class FragmentOptionsBackup extends FragmentBase implements SharedPrefere
 
         ibHelp = view.findViewById(R.id.ibHelp);
         btnExport = view.findViewById(R.id.btnExport);
+        tvExportPro = view.findViewById(R.id.tvExportPro);
         btnImport = view.findViewById(R.id.btnImport);
         cardCloud = view.findViewById(R.id.cardCloud);
         tvCloudInfo = view.findViewById(R.id.tvCloudInfo);
@@ -245,6 +247,7 @@ public class FragmentOptionsBackup extends FragmentBase implements SharedPrefere
 
         // Initialize
         FragmentDialogTheme.setBackground(getContext(), view, false);
+        Helper.linkPro(tvExportPro);
         cardCloud.setVisibility(
                 BuildConfig.DEBUG &&
                         Build.VERSION.SDK_INT >= Build.VERSION_CODES.O &&

app/src/main/res/layout/fragment_options_backup.xml

@@ -111,6 +111,17 @@
                     app:layout_constraintStart_toStartOf="parent"
                     app:layout_constraintTop_toBottomOf="@id/tvEncrypted" />
 
+                <TextView
+                    android:id="@+id/tvExportPro"
+                    android:layout_width="wrap_content"
+                    android:layout_height="wrap_content"
+                    android:layout_marginTop="12dp"
+                    android:text="@string/title_pro_feature"
+                    android:textAppearance="@style/TextAppearance.AppCompat.Small"
+                    android:textColor="?android:attr/textColorLink"
+                    app:layout_constraintStart_toStartOf="parent"
+                    app:layout_constraintTop_toBottomOf="@id/btnExport" />
+
                 <Button
                     android:id="@+id/btnImport"
                     style="?android:attr/buttonStyleSmall"
@@ -121,7 +132,7 @@
                     android:drawablePadding="6dp"
                     android:text="@string/title_setup_import"
                     app:layout_constraintStart_toStartOf="parent"
-                    app:layout_constraintTop_toBottomOf="@id/btnExport" />
+                    app:layout_constraintTop_toBottomOf="@id/tvExportPro" />
 
                 <TextView
                     android:id="@+id/tvScroll"