avoid Overlapping items in RelativeLayout for typing indicator

-> align Unread messages above typing_indicator_wrapper

Signed-off-by: Marcel Hibbe <dev@mhibbe.de>

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

@@ -117,12 +117,12 @@
             android:theme="@style/Button.Primary"
             android:layout_width="wrap_content"
             android:layout_height="wrap_content"
-            android:layout_alignParentBottom="true"
+            android:layout_alignBottom="@id/typing_indicator_wrapper"
             android:layout_centerHorizontal="true"
             android:layout_marginStart="64dp"
             android:layout_marginTop="16dp"
             android:layout_marginEnd="64dp"
-            android:layout_marginBottom="16dp"
+            android:layout_marginBottom="26dp"
             android:minHeight="@dimen/min_size_clickable_area"
             android:layout_toStartOf="@+id/scrollDownButton"
             android:text="@string/nc_new_messages"