update icu4j

Bug: #8703
Bug-Link: https://github.com/gwtproject/gwt/issues/8703
Change-Id: I79623cccc8c08e43deda70fc7b2b261a1866a4dd

dev/build.xml

diff --git a/dev/build.xml b/dev/build.xml
index e47beeb..263e641 100755
--- a/dev/build.xml
+++ b/dev/build.xml
@@ -80,7 +80,7 @@
           <include name="objectweb/asm-6.1.1/asm-commons-6.1.1.jar"/>
           <include name="objectweb/asm-6.1.1/asm-util-6.1.1.jar"/>
           <include name="guava/guava-19.0/guava-19.0-rebased.jar"/>
-          <include name="icu4j/50.1.1/icu4j.jar"/>
+          <include name="icu4j/63.1/icu4j.jar"/>
           <include name="jetty/jetty-9.2.14.v20151106/jetty-all-9.2.14.v20151106.jar"/>
           <include name="gson/gson-2.6.2.jar"/>
           <include name="jscomp/20160315/sourcemap-rebased.jar"/>
@@ -139,7 +139,7 @@
           <zipfileset
               src="${gwt.tools.lib}/eclipse/jdtCompilerAdapter_3.13.102-CUSTOM-GWT-20180415.jar"/>
           <zipfileset src="${gwt.tools.lib}/guava/guava-19.0/guava-19.0-rebased.jar"/>
-          <zipfileset src="${gwt.tools.lib}/icu4j/50.1.1/icu4j.jar"/>
+          <zipfileset src="${gwt.tools.lib}/icu4j/63.1/icu4j.jar"/>
           <zipfileset
               src="${gwt.tools.lib}/jetty/jetty-9.2.14.v20151106/jetty-all-9.2.14.v20151106.jar"/>
           <zipfileset src="${gwt.tools.lib}/gson/gson-2.6.2.jar"/>

maven/poms/gwt/pom-template.xml

diff --git a/maven/poms/gwt/pom-template.xml b/maven/poms/gwt/pom-template.xml
index aec1071..883e905 100644
--- a/maven/poms/gwt/pom-template.xml
+++ b/maven/poms/gwt/pom-template.xml
@@ -124,7 +124,7 @@
             <dependency>
                 <groupId>com.ibm.icu</groupId>
                 <artifactId>icu4j</artifactId>
-                <version>50.1.1</version>
+                <version>63.1</version>
             </dependency>
             <dependency>
                 <groupId>net.sourceforge.htmlunit</groupId>