Add missing nullability annotation and replace JSR 305

Author: offa

src/main/java/org/jenkinsci/plugins/parameterizedscheduler/DescriptorImpl.java

@@ -1,6 +1,8 @@
 package org.jenkinsci.plugins.parameterizedscheduler;
 
 import static hudson.Util.fixNull;
+
+import edu.umd.cs.findbugs.annotations.NonNull;
 import hudson.Extension;
 import hudson.model.Item;
 import hudson.model.AbstractProject;
@@ -38,6 +40,7 @@ public boolean isApplicable(Item item) {
 		return result;
 	}
 
+	@NonNull
 	@Override
 	public String getDisplayName() {
 		return Messages.ParameterizedTimerTrigger_DisplayName();

src/main/java/org/jenkinsci/plugins/parameterizedscheduler/ParameterParser.java

@@ -1,10 +1,10 @@
 package org.jenkinsci.plugins.parameterizedscheduler;
 
 import com.google.common.base.Splitter;
+import edu.umd.cs.findbugs.annotations.CheckForNull;
 import hudson.model.ParametersDefinitionProperty;
 import org.apache.commons.lang.StringUtils;
 
-import javax.annotation.CheckForNull;
 import java.util.Collections;
 import java.util.List;
 import java.util.Map;

src/test/java/org/jenkinsci/plugins/parameterizedscheduler/ParameterizedSchedulerTest.java

@@ -1,5 +1,7 @@
 package org.jenkinsci.plugins.parameterizedscheduler;
 
+import edu.umd.cs.findbugs.annotations.CheckForNull;
+import edu.umd.cs.findbugs.annotations.NonNull;
 import hudson.model.FreeStyleProject;
 import hudson.model.Job;
 import hudson.model.ParameterDefinition;
@@ -18,9 +20,6 @@
 import org.jvnet.hudson.test.JenkinsRule;
 import org.kohsuke.stapler.StaplerRequest;
 
-import javax.annotation.CheckForNull;
-import javax.annotation.Nonnull;
-
 import java.util.ArrayList;
 import java.util.List;
 
@@ -144,7 +143,7 @@ public void nullValueCreated() throws Exception {
 
     private static class NullParameterDefinition extends ParameterDefinition {
 
-        public NullParameterDefinition(@Nonnull String name) {
+        public NullParameterDefinition(@NonNull String name) {
             super(name, null);
         }