Enhance license detection for various licenses (#31198)

This commit enhances the license detection that we have for various
licenses. Here we improve the detection for all licenses (especially the
Apache 2.0 License), the BSD 2-clause license, the MIT (with
attribution) license, and we add detection for the BSD 3-clause
license. One way that we achieved this improvement is by changing how
the license files are read so that rather than reading them as a
multi-line string which ended up represented as "[line1, line2, line3,
...]" internally, we read the full bytes of the license text and replace
all whitespace with a single space so the license text is now loaded as
"line1 line2 line3". For the MIT license we add the actual license text
and remove the "MIT" string as not all copies of the license clearly
indicate that the text is the MIT license. We take a similar strategy
for the BSD-2 and BSD-3 clause licenses. With this change, we reduce the
number of "custom" licenses in the codebase from 31 to 2. The two
remaining appear to be truly custom licenses, not carrying licenses
identifiable by SPDX. A follow-up will address "unknown" licenses.

Author: jasontedor

buildSrc/src/main/groovy/org/elasticsearch/gradle/DependenciesInfoTask.groovy

@@ -109,7 +109,8 @@ public class DependenciesInfoTask extends DefaultTask {
         }
 
         if (license) {
-            final String content = license.readLines("UTF-8").toString()
+            // replace * because they are sometimes used at the beginning lines as if the license was a multi-line comment
+            final String content = new String(license.readBytes(), "UTF-8").replaceAll("\\s+", " ").replaceAll("\\*", " ")
             final String spdx = checkSPDXLicense(content)
             if (spdx ==  null) {
                 // License has not be identified as SPDX.
@@ -133,13 +134,84 @@ public class DependenciesInfoTask extends DefaultTask {
     private String checkSPDXLicense(final String licenseText) {
         String spdx = null
 
-        final String APACHE_2_0 = "Apache.*License.*(v|V)ersion 2.0"
-        final String BSD_2 = "BSD 2-clause.*License"
+        final String APACHE_2_0 = "Apache.*License.*(v|V)ersion.*2\\.0"
+
+        final String BSD_2 = """
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions
+are met:
+
+ 1\\. Redistributions of source code must retain the above copyright
+    notice, this list of conditions and the following disclaimer\\.
+ 2\\. Redistributions in binary form must reproduce the above copyright
+    notice, this list of conditions and the following disclaimer in the
+    documentation and/or other materials provided with the distribution\\.
+
+THIS SOFTWARE IS PROVIDED BY .+ (``|''|")AS IS(''|") AND ANY EXPRESS OR
+IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED\\.
+IN NO EVENT SHALL .+ BE LIABLE FOR ANY DIRECT, INDIRECT,
+INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES \\(INCLUDING, BUT
+NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION\\) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+\\(INCLUDING NEGLIGENCE OR OTHERWISE\\) ARISING IN ANY WAY OUT OF THE USE OF
+THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE\\.
+""".replaceAll("\\s+", "\\\\s*")
+
+        final String BSD_3 = """
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions
+are met:
+
+ (1\\.)? Redistributions of source code must retain the above copyright
+    notice, this list of conditions and the following disclaimer\\.
+ (2\\.)? Redistributions in binary form must reproduce the above copyright
+    notice, this list of conditions and the following disclaimer in the
+    documentation and/or other materials provided with the distribution\\.
+ ((3\\.)? The name of .+ may not be used to endorse or promote products
+    derived from this software without specific prior written permission\\.|
+  (3\\.)? Neither the name of .+ nor the names of its
+     contributors may be used to endorse or promote products derived from
+     this software without specific prior written permission\\.)  
+
+THIS SOFTWARE IS PROVIDED BY .+ (``|''|")AS IS(''|") AND ANY EXPRESS OR
+IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED\\.
+IN NO EVENT SHALL .+ BE LIABLE FOR ANY DIRECT, INDIRECT,
+INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES \\(INCLUDING, BUT
+NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION\\) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+\\(INCLUDING NEGLIGENCE OR OTHERWISE\\) ARISING IN ANY WAY OUT OF THE USE OF
+THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE\\.
+""".replaceAll("\\s+", "\\\\s*")
+
         final String CDDL_1_0 = "COMMON DEVELOPMENT AND DISTRIBUTION LICENSE.*Version 1.0"
         final String CDDL_1_1 = "COMMON DEVELOPMENT AND DISTRIBUTION LICENSE.*Version 1.1"
         final String ICU = "ICU License - ICU 1.8.1 and later"
         final String LGPL_3 = "GNU LESSER GENERAL PUBLIC LICENSE.*Version 3"
-        final String MIT = "MIT License"
+
+        final String MIT = """
+Permission is hereby granted, free of charge, to any person obtaining a copy of
+this software and associated documentation files \\(the "Software"\\), to deal in
+the Software without restriction, including without limitation the rights to
+use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
+of the Software, and to permit persons to whom the Software is furnished to do
+so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software\\.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT\\. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE\\.
+""".replaceAll("\\s+", "\\\\s*")
+
         final String MOZILLA_1_1 = "Mozilla Public License.*Version 1.1"
 
         switch (licenseText) {
@@ -152,6 +224,9 @@ public class DependenciesInfoTask extends DefaultTask {
             case ~/.*${BSD_2}.*/:
                 spdx = 'BSD-2-Clause'
                 break
+            case ~/.*${BSD_3}.*/:
+                spdx = 'BSD-3-Clause'
+                break
             case ~/.*${LGPL_3}.*/:
                 spdx = 'LGPL-3.0'
                 break