Remove flickering background on the app bar

Signed-off-by: sowjanyakch <sowjanya.kch@gmail.com>

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

@@ -36,7 +36,9 @@
         android:clipChildren="true"
         android:clipToPadding="false"
         android:windowContentOverlay="@null"
-        app:elevation="0dp">
+        app:elevation="0dp"
+        app:liftOnScrollTargetViewId="@id/recycler_view"
+        app:liftOnScrollColor="@color/bg_default">
 
         <com.google.android.material.card.MaterialCardView
             android:id="@+id/search_toolbar"