Boost default maxNumInstancesPerContainer (#3200)

diff --git a/heron/packing/src/java/org/apache/heron/packing/utils/PackingUtils.java b/heron/packing/src/java/org/apache/heron/packing/utils/PackingUtils.java
index 36ede38..8390711 100644
--- a/heron/packing/src/java/org/apache/heron/packing/utils/PackingUtils.java
+++ b/heron/packing/src/java/org/apache/heron/packing/utils/PackingUtils.java
@@ -40,7 +40,7 @@
   public static final ByteAmount DEFAULT_CONTAINER_RAM_PADDING = ByteAmount.fromGigabytes(1);
   public static final ByteAmount DEFAULT_CONTAINER_DISK_PADDING = ByteAmount.fromGigabytes(1);
   public static final double DEFAULT_CONTAINER_CPU_PADDING = 1.0;
-  public static final int DEFAULT_MAX_NUM_INSTANCES_PER_CONTAINER = 4;
+  public static final int DEFAULT_MAX_NUM_INSTANCES_PER_CONTAINER = 10;
 
   private PackingUtils() {
   }
diff --git a/heron/packing/tests/java/org/apache/heron/packing/CommonPackingTests.java b/heron/packing/tests/java/org/apache/heron/packing/CommonPackingTests.java
index d99ac92..9233afe 100644
--- a/heron/packing/tests/java/org/apache/heron/packing/CommonPackingTests.java
+++ b/heron/packing/tests/java/org/apache/heron/packing/CommonPackingTests.java
@@ -71,6 +71,7 @@
     // object Config and Topology objects. This is typically fine for packing tests since they don't
     // access the protobuf values.
     this.topologyConfig = new org.apache.heron.api.Config();
+    this.topologyConfig.setTopologyContainerMaxNumInstances(4);
     this.topology = getTopology(spoutParallelism, boltParallelism, topologyConfig);
 
     Config config = PackingTestUtils.newTestConfig(this.topology);