Upgrade Atomix dependency version to 2.0.2

Change-Id: I6559beff9cc49768aa07d7e08e84eabd96ecb862
diff --git a/core/store/primitives/src/main/java/org/onosproject/store/primitives/impl/StoragePartitionServer.java b/core/store/primitives/src/main/java/org/onosproject/store/primitives/impl/StoragePartitionServer.java
index 6028685..36b854f 100644
--- a/core/store/primitives/src/main/java/org/onosproject/store/primitives/impl/StoragePartitionServer.java
+++ b/core/store/primitives/src/main/java/org/onosproject/store/primitives/impl/StoragePartitionServer.java
@@ -16,6 +16,7 @@
 package org.onosproject.store.primitives.impl;
 
 import java.io.File;
+import java.time.Duration;
 import java.util.Collection;
 import java.util.concurrent.CompletableFuture;
 import java.util.function.Supplier;
@@ -41,6 +42,9 @@
 
     private static final int MAX_ENTRIES_PER_LOG_SEGMENT = 32768;
     private static final int MAX_SEGMENT_SIZE = 1024 * 1024 * 64;
+    private static final long ELECTION_TIMEOUT_MILLIS = 2500;
+    private static final long HEARTBEAT_INTERVAL_MILLIS = 1000;
+
     private final MemberId localMemberId;
     private final StoragePartition partition;
     private final Supplier<RaftServerProtocol> protocol;
@@ -98,8 +102,10 @@
         RaftServer.Builder builder = RaftServer.newBuilder(localMemberId)
                 .withName("partition-" + partition.getId())
                 .withProtocol(protocol.get())
+                .withElectionTimeout(Duration.ofMillis(ELECTION_TIMEOUT_MILLIS))
+                .withHeartbeatInterval(Duration.ofMillis(HEARTBEAT_INTERVAL_MILLIS))
                 .withStorage(RaftStorage.newBuilder()
-                        .withStorageLevel(StorageLevel.DISK)
+                        .withStorageLevel(StorageLevel.MAPPED)
                         .withSerializer(new AtomixSerializerAdapter(Serializer.using(StorageNamespaces.RAFT_STORAGE)))
                         .withDirectory(dataFolder)
                         .withMaxEntriesPerSegment(MAX_ENTRIES_PER_LOG_SEGMENT)