chore: parallellize keychain and queryPromise

Ticket: CAAS-7

Author: Gautam2305

modules/sdk-core/src/bitgo/wallet/wallet.ts

@@ -2176,25 +2176,25 @@ export class Wallet implements IWallet {
     }
 
     // Doing a sanity check for password here to avoid doing further work if we know it's wrong
-    const keychains = await this.getKeychainsAndValidatePassphrase({
-      reqId: params.reqId,
-      walletPassphrase: params.walletPassphrase,
-      customSigningFunction: params.customSigningFunction,
-    });
-
-    let txPrebuildQuery: Promise<PrebuildTransactionResult | string>;
-    if (isPrebuildTransactionResult(params.prebuildTx) && params.prebuildTx.buildParams?.preview) {
-      // If we prebuilt the txRequest with preview=true, then we should rebuild with preview=false to persist the request
-      txPrebuildQuery = this.prebuildTransaction({
-        ...params,
-        ...{ ...params.prebuildTx.buildParams, preview: false },
-      });
-    } else {
-      txPrebuildQuery = params.prebuildTx ? Promise.resolve(params.prebuildTx) : this.prebuildTransaction(params);
-    }
+    // Run keychain validation and tx prebuild in parallel
+    const [keychains, txPrebuild] = await Promise.all([
+      // Validate passphrase and get keychains
+      this.getKeychainsAndValidatePassphrase({
+        reqId: params.reqId,
+        walletPassphrase: params.walletPassphrase,
+        customSigningFunction: params.customSigningFunction,
+      }),
 
-    // the prebuild can be overridden by providing an explicit tx
-    const txPrebuild = (await txPrebuildQuery) as PrebuildTransactionResult;
+      (async () => {
+        if (isPrebuildTransactionResult(params.prebuildTx) && params.prebuildTx.buildParams?.preview) {
+          return this.prebuildTransaction({
+            ...params,
+            ...{ ...params.prebuildTx.buildParams, preview: false },
+          });
+        }
+        return params.prebuildTx ? Promise.resolve(params.prebuildTx) : this.prebuildTransaction(params);
+      })() as Promise<PrebuildTransactionResult>,
+    ]);
 
     try {
       await this.baseCoin.verifyTransaction({