8174977: Update license files with consistent license/notice names

Reviewed-by: alanb, mchung

jaxp/src/java.xml/share/legal/bcel.md

@@ -1,6 +1,6 @@
-## Apache Byte Code Engineering Library v5.2
+## Apache Byte Code Engineering Library (BCEL) v5.2
 
-### Notice
+### Apache BCEL Notice
 <pre>
 
     =========================================================================

jaxp/src/java.xml/share/legal/dom.md

@@ -1,6 +1,6 @@
-## DOM Level 3 core specification, v1.0
+## DOM Level 3 Core Specification v1.0
 
-## W3C License
+### W3C License
 <pre>
 
 W3C SOFTWARE NOTICE AND LICENSE

jaxp/src/java.xml/share/legal/xalan.md

@@ -1,6 +1,6 @@
 ## Apache Xalan v2.7.1
 
-### Notice
+### Apache Xalan Notice
 <pre>
 
     ======================================================================================

jaxp/src/java.xml/share/legal/xerces.md

@@ -1,7 +1,7 @@
 ## Apache Xerces v2.11.0
 
-### Notice
-
+### Apache Xerces Notice
+<pre>
     =========================================================================
     == NOTICE file corresponding to section 4(d) of the Apache License, ==
     == Version 2.0, in this case for the Apache Xerces Java distribution. ==
@@ -17,6 +17,7 @@
     - voluntary contributions made by Paul Eng on behalf of the
     Apache Software Foundation that were originally developed at iClick, Inc.,
     software copyright (c) 1999.
+</pre>
 
 ### Apache 2.0 License
 <pre>

jaxp/src/java.xml/share/legal/xmlresolver.md

@@ -1,6 +1,6 @@
 ## Apache XML Resolver Library v1.2
 
-### Notice
+### Apache XML Resolver Notice
 <pre>
 
 Apache XML Commons Resolver