Add manifest conditions

Check for the existence of the podman.socket for the Cockpit client
scenario.

src/manifest.json

@@ -1,4 +1,7 @@
 {
+    "conditions": [
+        {"path-exists": "/lib/systemd/system/podman.socket"}
+    ],
     "menu": {
         "index": {
             "label": "Podman containers",

test/check-application

@@ -2563,6 +2563,19 @@ class TestApplication(testlib.MachineCase):
         b.click(".pf-m-expanded button:contains('Logs')")
         b.wait_in_text(".pf-m-expanded .pf-c-empty-state__content", "failed to obtain logs for Container")
 
+    def testManifest(self):
+        b = self.browser
+        m = self.machine
+        self.restore_file("/lib/systemd/system/podman.socket")
+        m.execute("rm /lib/systemd/system/podman.socket")
+        self.login_and_go(None)
+        b.wait_in_text("#host-apps .pf-m-current", "Overview")
+
+        if self.is_pybridge():
+            self.assertIn("Podman", b.text("#host-apps .pf-m-current"))
+        else:
+            self.assertNotIn("Podman", b.text("#host-apps .pf-m-current"))
+
 
 if __name__ == '__main__':
     testlib.test_main()