Address code review comments

Author: tejasd

firebase-perf/src/main/java/com/google/firebase/perf/session/FirebasePerformanceSessionSubscriber.kt

@@ -1,5 +1,5 @@
 /*
- * Copyright 2024 Google LLC
+ * Copyright 2025 Google LLC
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -21,13 +21,10 @@ import com.google.firebase.perf.v1.ApplicationProcessState
 import com.google.firebase.sessions.api.SessionSubscriber
 import java.util.UUID
 
-class FirebasePerformanceSessionSubscriber(private val dataCollectionEnabled: Boolean) :
+class FirebasePerformanceSessionSubscriber(override val isDataCollectionEnabled: Boolean) :
   SessionSubscriber {
-  override val isDataCollectionEnabled: Boolean
-    get() = dataCollectionEnabled
 
-  override val sessionSubscriberName: SessionSubscriber.Name
-    get() = SessionSubscriber.Name.PERFORMANCE
+  override val sessionSubscriberName: SessionSubscriber.Name = SessionSubscriber.Name.PERFORMANCE
 
   override fun onSessionChanged(sessionDetails: SessionSubscriber.SessionDetails) {
     val currentPerfSession = SessionManager.getInstance().perfSession()

firebase-perf/src/main/java/com/google/firebase/perf/session/PerfSession.java

@@ -67,11 +67,12 @@ public String sessionId() {
   }
 
   /** Returns the AQS sessionId for the given session. */
+  @Nullable
   public String aqsSessionId() {
     return aqsSessionId;
   }
 
-  /** Returns the AQS sessionId for the given session. */
+  /** Sets the AQS sessionId for the given session. */
   public void setAQSId(SessionSubscriber.SessionDetails aqs) {
     if (aqsSessionId == null) {
       aqsSessionId = aqs.getSessionId();