[FIX] web: fix statusbar field not displaying correct value in mobile

Previously, the statusbar field didn't display the currently selected
value for selection field in mobile, as the getter to compute the name
of the currently selected item only accounted for the many2one case but
not for the selection field case.

This commit adds handling for the selection field case and a test for
it.

Part-of: odoo/odoo#78221

addons/web/static/src/views/fields/statusbar/statusbar_field.js

@@ -20,8 +20,17 @@ export class StatusBarField extends Component {
     }
 
     get currentName() {
-        const item = this.options.find((item) => item.isSelected);
-        return item ? item.name : "";
+        switch (this.props.record.fields[this.props.name].type) {
+            case "many2one": {
+                const item = this.options.find((item) => item.isSelected);
+                return item ? item.name : "";
+            }
+            case "selection": {
+                const item = this.options.find((item) => item[0] === this.props.value);
+                return item ? item[1] : "";
+            }
+        }
+        throw new Error("Unsupported field type for StatusBarField");
     }
     get options() {
         switch (this.props.record.fields[this.props.name].type) {

addons/web/static/tests/views/fields/statusbar_field_tests.js

@@ -166,6 +166,37 @@ QUnit.module("Fields", (hooks) => {
         );
     });
 
+    QUnit.test(
+        "folded statusbar widget on selection field has selected value in the toggler",
+        async function (assert) {
+            registry.category("services").add("ui", {
+                start(env) {
+                    Object.defineProperty(env, "isSmall", {
+                        value: true,
+                    });
+                    return {
+                        size: 0,
+                        isSmall: true,
+                    };
+                },
+            });
+            await makeView({
+                type: "form",
+                resModel: "partner",
+                resId: 1,
+                serverData,
+                arch: `
+                <form>
+                    <header>
+                        <field name="color" widget="statusbar" />
+                    </header>
+                </form>`,
+            });
+
+            assert.containsOnce(target, ".o_statusbar_status button.dropdown-toggle:contains(Red)");
+        }
+    );
+
     QUnit.test("static statusbar widget on many2one field with domain", async function (assert) {
         assert.expect(1);