Update TabletsMetadata stream() to autoclose TabletsMetadata (apache#4356)

Follow on changes to apache#4355 

Before this change if stream() was used the the TabletsMetadata close
method still had to be called manually as the close method on the stream
did not delegate. With this change if the stream is used in a
try-with-resources to autoClsoe the stream or if the stream is closed
manually, TabletsMetadata will also be closed.

Author: cshannon

core/src/main/java/org/apache/accumulo/core/clientImpl/bulk/ConcurrentKeyExtentCache.java

@@ -89,8 +89,7 @@ protected void updateCache(KeyExtent e) {
   protected Stream<KeyExtent> lookupExtents(Text row) {
     TabletsMetadata tabletsMetadata = TabletsMetadata.builder(ctx).forTable(tableId)
         .overlapping(row, true, null).checkConsistency().fetch(PREV_ROW).build();
-    return tabletsMetadata.stream().onClose(tabletsMetadata::close).limit(100)
-        .map(TabletMetadata::getExtent);
+    return tabletsMetadata.stream().limit(100).map(TabletMetadata::getExtent);
   }
 
   @Override

server/gc/src/main/java/org/apache/accumulo/gc/GCRun.java

@@ -175,9 +175,8 @@ public Stream<Reference> getReferences() {
     if (level == Ample.DataLevel.ROOT) {
       tabletStream = Stream.of(context.getAmple().readTablet(RootTable.EXTENT, DIR, FILES, SCANS));
     } else {
-      TabletsMetadata tm = TabletsMetadata.builder(context).scanTable(level.metaTable())
-          .checkConsistency().fetch(DIR, FILES, SCANS).build();
-      tabletStream = tm.stream().onClose(tm::close);
+      tabletStream = TabletsMetadata.builder(context).scanTable(level.metaTable())
+          .checkConsistency().fetch(DIR, FILES, SCANS).build().stream();
     }
 
     // there is a lot going on in this "one line" so see below for more info

server/tserver/src/main/java/org/apache/accumulo/tserver/ScanServer.java

@@ -159,8 +159,8 @@ private TabletMetadataLoader(Ample ample) {
       Collection<KeyExtent> extents = (Collection<KeyExtent>) keys;
       try (TabletsMetadata tabletsMetadata =
           ample.readTablets().forTablets(extents, Optional.empty()).build()) {
-        tms = tabletsMetadata.stream().onClose(tabletsMetadata::close)
-            .collect(Collectors.toMap(TabletMetadata::getExtent, tm -> tm));
+        tms =
+            tabletsMetadata.stream().collect(Collectors.toMap(TabletMetadata::getExtent, tm -> tm));
       }
       long t2 = System.currentTimeMillis();
       LOG.trace("Read metadata for {} tablets in {} ms", keys.size(), t2 - t1);