feat: multiplexed session as default session mode

.github/sync-repo-settings.yaml

@@ -7,7 +7,7 @@ branchProtectionRules:
     requiredStatusCheckContexts:
       - "ci/kokoro: Samples test"
       - "ci/kokoro: System test"
-      - "ci/kokoro: System test with Multiplexed Session"
+      - "ci/kokoro: System test with Regular Sessions"
       - lint
       - test (18)
       - test (20)

observability-test/helper.ts

@@ -19,23 +19,26 @@ import * as assert from 'assert';
 const {ReadableSpan} = require('@opentelemetry/sdk-trace-base');
 import {SEMATTRS_DB_NAME} from '@opentelemetry/semantic-conventions';
 
+export const createSessionEvents = [
+  'Requesting a multiplexed session',
+  'Created a multiplexed session',
+];
+
 export const batchCreateSessionsEvents = [
   'Requesting 25 sessions',
   'Creating 25 sessions',
   'Requested for 25 sessions returned 25',
 ];
 
 export const waitingSessionsEvents = [
-  'Acquiring session',
-  'Waiting for a session to become available',
-  'Acquired session',
+  'Waiting for a multiplexed session to become available',
+  'Acquired multiplexed session',
   'Using Session',
 ];
 
 export const cacheSessionEvents = [
-  'Acquiring session',
-  'Cache hit: has usable session',
-  'Acquired session',
+  'Cache hit: has usable multiplexed session',
+  'Acquired multiplexed session',
 ];
 
 /**