fix: nullish coalescing operator

Author: avi-alpert

server/aws-lsp-codewhisperer/src/language-server/agenticChat/tabBarController.ts

@@ -270,9 +270,6 @@ export class TabBarController {
             return
         }
         this.#loadedChats = true
-
-        const dbSize = this.#chatHistoryDb.getDatabaseFileSize()
-
         const openConversations = this.#chatHistoryDb.getOpenTabs()
         if (openConversations) {
             for (const conversation of openConversations) {
@@ -281,8 +278,8 @@ export class TabBarController {
                 }
             }
             this.#telemetryService.emitLoadHistory({
-                amazonqTimeToLoadHistory: this.#chatHistoryDb.getLoadTime() || -1,
-                amazonQHistoryFileSize: dbSize || -1,
+                amazonqTimeToLoadHistory: this.#chatHistoryDb.getLoadTime() ?? -1,
+                amazonQHistoryFileSize: this.#chatHistoryDb.getDatabaseFileSize() ?? -1,
                 openTabCount: openConversations.length,
                 languageServerVersion: this.#features.runtime.serverInfo.version,
             })