Device manager - extract filtered device list header (#9323)

* extract filtered device list header

* stylelint

test/components/views/settings/tabs/user/SessionManagerTab-test.tsx

@@ -279,7 +279,7 @@ describe('<SessionManagerTab />', () => {
         await flushPromisesWithFakeTimers();
 
         // unverified filter is set
-        expect(container.querySelector('.mx_FilteredDeviceList_header')).toMatchSnapshot();
+        expect(container.querySelector('.mx_FilteredDeviceListHeader')).toMatchSnapshot();
     });
 
     describe('device detail expansion', () => {

test/components/views/settings/tabs/user/__snapshots__/SessionManagerTab-test.tsx.snap

@@ -17,10 +17,10 @@ exports[`<SessionManagerTab /> Sign out Signs out of current device 1`] = `
 
 exports[`<SessionManagerTab /> goes to filtered list from security recommendations 1`] = `
 <div
-  class="mx_FilteredDeviceList_header"
+  class="mx_FilteredDeviceListHeader"
 >
   <span
-    class="mx_FilteredDeviceList_headerLabel"
+    class="mx_FilteredDeviceListHeader_label"
   >
     Sessions
   </span>