Add AsyncQueryHandler helper for queryEntities().

Recently we added queryEntities() to the ContentProvider
interface to read out Entity objects atomically.  This
change adds a helper to AsyncQueryHandler to perform these
queries on a background thread, returning the result when
finished.

api/current.xml

@@ -27892,6 +27892,23 @@
 <parameter name="cursor" type="android.database.Cursor">
 </parameter>
 </method>
+<method name="onQueryEntitiesComplete"
+ return="void"
+ abstract="false"
+ native="false"
+ synchronized="false"
+ static="false"
+ final="false"
+ deprecated="not deprecated"
+ visibility="protected"
+>
+<parameter name="token" type="int">
+</parameter>
+<parameter name="cookie" type="java.lang.Object">
+</parameter>
+<parameter name="iterator" type="android.content.EntityIterator">
+</parameter>
+</method>
 <method name="onUpdateComplete"
  return="void"
  abstract="false"
@@ -27974,6 +27991,29 @@
 <parameter name="orderBy" type="java.lang.String">
 </parameter>
 </method>
+<method name="startQueryEntities"
+ return="void"
+ abstract="false"
+ native="false"
+ synchronized="false"
+ static="false"
+ final="false"
+ deprecated="not deprecated"
+ visibility="public"
+>
+<parameter name="token" type="int">
+</parameter>
+<parameter name="cookie" type="java.lang.Object">
+</parameter>
+<parameter name="uri" type="android.net.Uri">
+</parameter>
+<parameter name="selection" type="java.lang.String">
+</parameter>
+<parameter name="selectionArgs" type="java.lang.String[]">
+</parameter>
+<parameter name="orderBy" type="java.lang.String">
+</parameter>
+</method>
 <method name="startUpdate"
  return="void"
  abstract="false"