Add missing dependency to build.

Change-Id: I2e46fa275cf3459de0206486517c89f55033dd18
diff --git a/build.gradle b/build.gradle
index eb268f9..8a6e218 100644
--- a/build.gradle
+++ b/build.gradle
@@ -367,6 +367,7 @@
                 "openjdk/openjdk-rt-1.8",
                 "openjdk/desugar_jdk_libs",
                 "openjdk/desugar_jdk_libs_11",
+                "openjdk/desugar_jdk_libs_legacy",
                 "openjdk/desugar_jdk_libs_releases/1.0.9",
                 "openjdk/desugar_jdk_libs_releases/1.0.10",
                 "openjdk/desugar_jdk_libs_releases/1.1.0",