Addressed PR comments

Author: prsaminathan

common4j/src/main/com/microsoft/identity/common/java/broker/IBrokerPerformanceMetricsProvider.kt

@@ -23,5 +23,5 @@
 package com.microsoft.identity.common.java.broker
 
 interface IBrokerPerformanceMetricsProvider {
-    var brokerPerformanceMetrics: BrokerPerformanceMetrics?
+    val brokerPerformanceMetrics: BrokerPerformanceMetrics?
 }

common4j/src/main/com/microsoft/identity/common/java/exception/BaseException.java

@@ -224,6 +224,7 @@ public void setBrokerPerformanceMetrics(final BrokerPerformanceMetrics brokerPer
         this.mBrokerPerformanceMetrics = brokerPerformanceMetrics;
     }
 
+    @Override
     public BrokerPerformanceMetrics getBrokerPerformanceMetrics() {
         return this.mBrokerPerformanceMetrics;
     }

common4j/src/main/com/microsoft/identity/common/java/result/AcquireTokenResult.java

@@ -61,6 +61,7 @@ public void setBrokerPerformanceMetrics(BrokerPerformanceMetrics brokerPerforman
         this.mBrokerPerformanceMetrics = brokerPerformanceMetrics;
     }
 
+    @Override
     public BrokerPerformanceMetrics getBrokerPerformanceMetrics() {
         return this.mBrokerPerformanceMetrics;
     }