Added preview scroll hint

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

@@ -575,6 +575,19 @@
             app:layout_constraintStart_toStartOf="parent"
             app:layout_constraintTop_toBottomOf="@id/tvPreviewLines" />
 
+        <TextView
+            android:id="@+id/tvPreviewIssue"
+            android:layout_width="0dp"
+            android:layout_height="wrap_content"
+            android:layout_marginTop="6dp"
+            android:layout_marginEnd="48dp"
+            android:text="@string/title_advanced_preview_issue"
+            android:textAppearance="@style/TextAppearance.AppCompat.Small"
+            android:textStyle="italic"
+            app:layout_constraintEnd_toEndOf="parent"
+            app:layout_constraintStart_toStartOf="parent"
+            app:layout_constraintTop_toBottomOf="@id/spPreviewLines" />
+
         <androidx.appcompat.widget.SwitchCompat
             android:id="@+id/swAddresses"
             android:layout_width="0dp"
@@ -583,7 +596,7 @@
             android:text="@string/title_advanced_addresses"
             app:layout_constraintEnd_toEndOf="parent"
             app:layout_constraintStart_toStartOf="parent"
-            app:layout_constraintTop_toBottomOf="@id/spPreviewLines"
+            app:layout_constraintTop_toBottomOf="@id/tvPreviewIssue"
             app:switchPadding="12dp" />
 
         <androidx.appcompat.widget.SwitchCompat

app/src/main/res/values/strings.xml

@@ -432,6 +432,7 @@
     <string name="title_advanced_gravatars_hint">There might be a privacy risk</string>
     <string name="title_advanced_name_email_hint">When disabled only names will be shown when available</string>
     <string name="title_advanced_preview_hint">Only available when message text has been downloaded</string>
+    <string name="title_advanced_preview_issue">Scrolling can be slow due to a bug in some Android versions when the number of lines is more than one</string>
     <string name="title_advanced_inline_hint">Inline images are images included in the message</string>
 
     <string name="title_advanced_autoexpand_hint">Automatically open message when there is just one message or just one unread message in a conversation</string>