[zxdb] Soft transition updateAsyncBacktrace DAP event name [1/2]

This adds support for the new name of the updateAsyncBacktrace custom
DAP event that is sent by zxdb to populate the async-backtrace pane in
IDEs that support the Fuchsia extension.

Both names are accepted for now. A later CL will remove support for the
old name.

Bug: 507026507
Change-Id: Id72815aed5b3e9ec876bea6e8e925663094894ae
Reviewed-on: https://fuchsia-review.googlesource.com/c/vscode-plugins/+/1590568
Reviewed-by: Darren Chan <chandarren@google.com>
Kokoro: Kokoro <noreply+kokoro@google.com>

src/zxdb/async_backtrace.ts

diff --git a/src/zxdb/async_backtrace.ts b/src/zxdb/async_backtrace.ts
index 27b4426..d8d8671 100644
--- a/src/zxdb/async_backtrace.ts
+++ b/src/zxdb/async_backtrace.ts
@@ -10,7 +10,9 @@
 import { Setup } from '../extension';
 
 const kSessionType = 'zxdb';
+// TODO(https://fxbug.dev/507026507): Remove the old name after soft transitioning.
 const kEventName = 'vscode-fuchsia.updateAsyncBacktrace';
+const kNewEventName = 'zxdb.updateAsyncBacktrace';
 export const kMaxLabelLength = 35;
 
 // This needs to match the `AsyncTaskNode` struct in the DAP server implementation:
@@ -277,7 +279,7 @@
     process.cwd(),
   );
   const asyncBacktraceUpdateListener = vscode.debug.onDidReceiveDebugSessionCustomEvent((e) => {
-    if (e.session.type !== kSessionType || e.event !== kEventName) {
+    if (e.session.type !== kSessionType || !(e.event === kEventName || e.event === kNewEventName)) {
       return;
     }