refactor: rename SendSending to LongSend; revert unrelated test changes

- Rename LiveRegion/SendSending.tsx -> LiveRegion/LongSend.tsx
- Rename component LiveRegionSendSending -> LiveRegionLongSend
- Revert unknownActivity.html, fluentTheme/suggestedActions.html,
  updateActivity/sameActivityId.html to base (unrelated test fixes)
- Revert videoCard.html.snap-1.png to base (spurious 1-byte PNG artifact)

Author: isherstneva

__tests__/html2/accessibility/liveRegion/attachment/videoCard.html.snap-1.png

@@ -70,13 +70,6 @@
         expect(consoleError.mock.calls[0][0].message).toBe('No renderer for activity of type "x-unknown-activity"');
 
         // THEN: Should emit as exception event.
-        // The telemetry event fires asynchronously; wait for it to appear.
-        await pageConditions.became(
-          'telemetry exception event for unknown activity',
-          () => onTelemetry.mock.calls.some(call => call[0]?.type === 'exception'),
-          2000
-        );
-
         const exceptionEvent = onTelemetry.mock.calls.find(call => call[0]?.type === 'exception');
 
         expect(exceptionEvent).toBeTruthy();

__tests__/html2/activity/legacy/unknownActivity.html

@@ -97,7 +97,6 @@
         });
 
         // THEN: Should render the activity.
-        await pageConditions.allImagesLoaded();
         await host.snapshot('local');
       });
     </script>

__tests__/html2/fluentTheme/suggestedActions.html

@@ -55,7 +55,6 @@
         // THEN: Bot should reply with 2 messages. However, we change their `activity.id` to be the same value.
         //       Thus, only the second message will be shown. And there are 2 messages in total only.
         await pageConditions.numActivitiesShown(2);
-        await pageConditions.scrollToBottomCompleted();
 
         // THEN: It should show 1 outgoing message, and 1 incoming message.
         await host.snapshot('local');

__tests__/html2/updateActivity/sameActivityId.html

@@ -18,7 +18,7 @@ const SENDING_ANNOUNCEMENT_DELAY = 3000;
  *
  * Presentational activities (e.g. `event` or `typing`) are excluded to reduce noise.
  */
-const LiveRegionSendSending = () => {
+const LiveRegionLongSend = () => {
   const [sendStatusByActivityKey] = useSendStatusByActivityKey();
   const getActivityByKey = useGetActivityByKey();
   const localize = useLocalizer();
@@ -93,6 +93,6 @@ const LiveRegionSendSending = () => {
   return null;
 };
 
-LiveRegionSendSending.displayName = 'LiveRegionSendSending';
+LiveRegionLongSend.displayName = 'LiveRegionLongSend';
 
-export default memo(LiveRegionSendSending);
+export default memo(LiveRegionLongSend);

…rc/Transcript/LiveRegion/SendSending.tsx …t/src/Transcript/LiveRegion/LongSend.tsxpackages/component/src/Transcript/LiveRegion/SendSending.tsx renamed to packages/component/src/Transcript/LiveRegion/LongSend.tsx packages/component/src/Transcript/LiveRegion/SendSending.tsx renamed to packages/component/src/Transcript/LiveRegion/LongSend.tsx

@@ -9,7 +9,7 @@ import useLocalizeAccessKey from '../hooks/internal/useLocalizeAccessKey';
 import useSuggestedActionsAccessKey from '../hooks/internal/useSuggestedActionsAccessKey';
 import { useQueueStaticElement } from '../providers/LiveRegionTwin';
 import LiveRegionSendFailed from './LiveRegion/SendFailed';
-import LiveRegionSendSending from './LiveRegion/SendSending';
+import LiveRegionLongSend from './LiveRegion/LongSend';
 import isPresentational from './LiveRegion/isPresentational';
 import useTypistNames from './useTypistNames';
 
@@ -134,7 +134,7 @@ const LiveRegionTranscript = ({ activityElementMapRef }: LiveRegionTranscriptPro
   return (
     <React.Fragment>
       <LiveRegionSendFailed />
-      <LiveRegionSendSending />
+      <LiveRegionLongSend />
     </React.Fragment>
   );
 };