Show dropdown arrow for hostel selection in MessMenuFragment

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

@@ -8,14 +8,20 @@
         android:orientation="vertical"
         tools:context="app.insti.fragment.MessMenuFragment">
 
-        <Spinner
-            android:id="@+id/hostel_spinner"
+        <FrameLayout
             android:layout_width="match_parent"
             android:layout_height="wrap_content"
-            android:background="@color/colorPrimary"
-            android:paddingBottom="12dp"
-            android:paddingLeft="16dp"
-            android:theme="@style/AppTheme" />
+            android:background="@color/colorPrimary">
+
+            <Spinner
+                android:id="@+id/hostel_spinner"
+                android:layout_width="wrap_content"
+                android:layout_height="wrap_content"
+                android:layout_marginBottom="12dp"
+                android:paddingLeft="16dp"
+                android:backgroundTint="@color/colorWhite"
+                android:theme="@style/AppTheme" />
+        </FrameLayout>
 
         <android.support.v4.widget.SwipeRefreshLayout
             android:id="@+id/mess_menu_swipe_refresh_layout"