[IMP] hr_expense: add image on nocontent helper

The nocontent helper now shows a more descriptive image and a link to
the mobile application.

closes odoo/odoo#52972

Taskid: 2277641
Signed-off-by: Yannick Tivisse (yti) <yti@odoo.com>

addons/hr_expense/static/src/scss/hr_expense.scss

@@ -21,3 +21,14 @@
         color: $o-enterprise-color;
     }
 }
+.o_view_nocontent {
+    .o_nocontent_help {
+        .o_view_nocontent_expense_receipt:before {
+            @extend %o-nocontent-init-image;
+            @include size(300px, 230px);
+            background: transparent url(/hr_expense/static/img/nocontent.png) no-repeat center;
+            background-size: 300px 230px;
+            margin-bottom: 1rem;
+        }
+    }
+}

addons/hr_expense/views/hr_expense_views.xml

@@ -297,9 +297,18 @@
             <field name="search_view_id" ref="hr_expense_view_search"/>
             <field name="context">{'search_default_my_expenses': 1, 'search_default_no_report': 1}</field>
             <field name="help" type="html">
-              <p class="o_view_nocontent_smiling_face">
-                Create a new expense
-              </p>
+                <p class="o_view_nocontent_expense_receipt">
+                    Did you try the mobile app?
+                </p>
+                <p>Snap pictures of your receipts and let Odoo<br/> automatically create expenses for you.</p>
+                <p>
+                    <a href="https://apps.apple.com/be/app/odoo/id1272543640" target="_blank">
+                        <img alt="Apple App Store" class="img img-fluid h-100" src="/hr_expense/static/img/app_store.png"/>
+                    </a>
+                    <a href="https://play.google.com/store/apps/details?id=com.odoo.mobile" target="_blank">
+                        <img alt="Google Play Store" class="img img-fluid h-100" src="/hr_expense/static/img/play_store.png"/>
+                    </a>
+                </p>
             </field>
         </record>