ICU-23247 Fewer warnings when generating icu4j

Author: mihnita

icu4j/main/icu4j/pom.xml

@@ -72,21 +72,13 @@
       <plugin>
         <artifactId>maven-shade-plugin</artifactId>
         <executions>
-          <execution>
-            <id>source-jar</id>
-            <goals>
-              <goal>shade</goal>
-            </goals>
-            <configuration>
-              <createSourcesJar>true</createSourcesJar>
-            </configuration>
-          </execution>
           <execution>
             <goals>
               <goal>shade</goal>
             </goals>
             <phase>package</phase>
             <configuration>
+              <createSourcesJar>true</createSourcesJar>
               <createDependencyReducedPom>true</createDependencyReducedPom>
               <dependencyReducedPomLocation>${project.build.directory}/dependency-reduced-pom.xml</dependencyReducedPomLocation>
               <promoteTransitiveDependencies>true</promoteTransitiveDependencies>
@@ -97,6 +89,8 @@
                   <excludes>
                     <!-- Exclude taglets code -->
                     <exclude>com/ibm/icu/dev/tool/docs/**</exclude>
+                    <!-- We exclude the manifests in dependencies -->
+                    <exclude>META-INF/MANIFEST.MF</exclude>
                     <!-- Exclude maven info for unpublished artifacts -->
                     <exclude>META-INF/maven/com.ibm.icu/core/**</exclude>
                     <exclude>META-INF/maven/com.ibm.icu/tools_taglets/**</exclude>

pom.xml

@@ -133,7 +133,7 @@
     <mf.Specification-Version>${icu.major.version}</mf.Specification-Version>
     <mf.Implementation-Version>${project.version}</mf.Implementation-Version>
     <mf.Bundle-Version>${project.version}</mf.Bundle-Version>
-    <mf.Bundle-RequiredExecutionEnvironment>JavaSE-1.8</mf.Bundle-RequiredExecutionEnvironment>
+    <mf.Bundle-RequiredExecutionEnvironment>JavaSE-${maven.compiler.release}</mf.Bundle-RequiredExecutionEnvironment>
 
     <!-- For most modules artifactId does not have an "icu4j" prefix, so this is a good default -->
     <module-name>${project.artifactId}</module-name>