[FIX] web: navbar menu not shown on tablet

Before this fix, 'currentApp' returned 'undefined' on mobile but
there is no reason not to return the current app on mobile.
This has been fixed in enterprise repository.

Now that 'currentApp' returns a value, we have to explicitly hide
'menuItem' for small screen.

Steps to reproduce:
* Open Odoo on tablet
* Select an App => BUG

opw-2687424
opw-2688832

closes odoo/odoo#80639

X-original-commit: 3659d65f37d08737f99d62ecb8cd486ba8d764f4
Related: odoo/enterprise#22620
Signed-off-by: Adrien Dieudonné (adr) <adr@odoo.com>
Signed-off-by: Romeo Fragomeli (rfr) <rfr@odoo.com>

addons/web/static/src/webclient/navbar/navbar.xml

@@ -15,7 +15,7 @@
 
         <!-- App Brand -->
         <MenuItem
-          t-if="currentApp"
+          t-if="currentApp and !env.isSmall"
           href="getMenuItemHref(currentApp)"
           payload="currentApp"
           t-esc="currentApp.name"
@@ -24,7 +24,7 @@
         />
 
         <!-- Current App Sections -->
-        <t t-if="currentAppSections.length" t-call="web.NavBar.SectionsMenu">
+        <t t-if="currentAppSections.length and !env.isSmall" t-call="web.NavBar.SectionsMenu">
           <t t-set="sections" t-value="currentAppSections" />
         </t>