Make constructor of DeviceMemoryBufferView and ContiguousTable public

java/src/main/java/ai/rapids/cudf/ContiguousTable.java

@@ -42,7 +42,7 @@ static ContiguousTable fromPackedTable(long metadataHandle,
   }
 
   /** Construct a contiguous table instance given a table and the device buffer backing it. */
-  ContiguousTable(Table table, DeviceMemoryBuffer buffer) {
+  public ContiguousTable(Table table, DeviceMemoryBuffer buffer) {
     this.meta = new PackedColumnMetadata(createPackedMetadata(table.getNativeView(),
             buffer.getAddress(), buffer.getLength()));
     this.table = table;

java/src/main/java/ai/rapids/cudf/DeviceMemoryBufferView.java

@@ -24,7 +24,7 @@
  * that is backing it.
  */
 public class DeviceMemoryBufferView extends BaseDeviceMemoryBuffer {
-  DeviceMemoryBufferView(long address, long lengthInBytes) {
+  public DeviceMemoryBufferView(long address, long lengthInBytes) {
     // Set the cleaner to null so we don't end up releasing anything
     super(address, lengthInBytes, (MemoryBufferCleaner) null);
   }