Update desugared library in third_party to 1.1.3

This updates the desugared library in third_party/openjdk/desugared_jdk_libs
to version 1.1.3 (https://github.com/google/desugar_jdk_libs/commit/4df9570f26ac93c82bf881cdc18346e10056d72f).

The JAR is built on the bot and copied from
gs://r8-releases/raw/desugar_jdk_libs/1.1.3/desugar_jdk_libs.jar

This also renames the JAR from libjava.jar to desugar_jdk_libs.jar.

Content of README.google:

Name: desugar_jdk_libs
URL: https://github.com/google/desugar_jdk_libs
Version: 4df9570f26ac93c82bf881cdc18346e10056d72f
Revision: N/A
Date: Feb 15 2021
License: The GNU General Public License (GPL) (see LICENSE)

Description:
This project contains a small subset of OpenJDK libraries simplified for use on older runtimes.

Bug: 179397308
Change-Id: If35a1083bcdf8161ca425490637398028327700d
diff --git a/tools/utils.py b/tools/utils.py
index dcfa4f8..5d63a51 100644
--- a/tools/utils.py
+++ b/tools/utils.py
@@ -63,7 +63,7 @@
 DESUGAR_CONFIGURATION = os.path.join(
       'src', 'library_desugar', 'desugar_jdk_libs.json')
 DESUGAR_IMPLEMENTATION = os.path.join(
-      'third_party', 'openjdk', 'desugar_jdk_libs', 'libjava.jar')
+      'third_party', 'openjdk', 'desugar_jdk_libs', 'desugar_jdk_libs.jar')
 DESUGAR_CONFIGURATION_MAVEN_ZIP = os.path.join(
   LIBS, 'desugar_jdk_libs_configuration.zip')
 GENERATED_LICENSE = os.path.join(GENERATED_LICENSE_DIR, 'LICENSE')