Suppress warnings for spotbugs 4.8.3 (#611)

Plugin pom 4.77 needs this change to resolve new spotbugs warnings
that will be reported by spotbugs 4.8.3 and later.

Confirmed that the spotbugs warnings are visible when using the
4.77-SNAPSHOT plugin pom before this change. With this change, the
spotbugs warnings are no longer visible.

src/main/java/org/jenkins/plugins/lockableresources/LockStep.java

@@ -3,6 +3,7 @@
 import edu.umd.cs.findbugs.annotations.CheckForNull;
 import edu.umd.cs.findbugs.annotations.NonNull;
 import edu.umd.cs.findbugs.annotations.Nullable;
+import edu.umd.cs.findbugs.annotations.SuppressFBWarnings;
 import hudson.Extension;
 import hudson.model.AutoCompletionCandidates;
 import hudson.model.Item;
@@ -32,24 +33,32 @@ public class LockStep extends Step implements Serializable {
     private static final long serialVersionUID = -953609907239674360L;
 
     @CheckForNull
+    @SuppressFBWarnings(value = "PA_PUBLIC_PRIMITIVE_ATTRIBUTE", justification = "Preserve API compatibility.")
     public String resource = null;
 
     @CheckForNull
+    @SuppressFBWarnings(value = "PA_PUBLIC_PRIMITIVE_ATTRIBUTE", justification = "Preserve API compatibility.")
     public String label = null;
 
+    @SuppressFBWarnings(value = "PA_PUBLIC_PRIMITIVE_ATTRIBUTE", justification = "Preserve API compatibility.")
     public int quantity = 0;
 
     /** name of environment variable to store locked resources in */
     @CheckForNull
+    @SuppressFBWarnings(value = "PA_PUBLIC_PRIMITIVE_ATTRIBUTE", justification = "Preserve API compatibility.")
     public String variable = null;
 
+    @SuppressFBWarnings(value = "PA_PUBLIC_PRIMITIVE_ATTRIBUTE", justification = "Preserve API compatibility.")
     public boolean inversePrecedence = false;
 
+    @SuppressFBWarnings(value = "PA_PUBLIC_PRIMITIVE_ATTRIBUTE", justification = "Preserve API compatibility.")
     public String resourceSelectStrategy = ResourceSelectStrategy.SEQUENTIAL.name();
 
+    @SuppressFBWarnings(value = "PA_PUBLIC_PRIMITIVE_ATTRIBUTE", justification = "Preserve API compatibility.")
     public boolean skipIfLocked = false;
 
     @CheckForNull
+    @SuppressFBWarnings(value = "PA_PUBLIC_PRIMITIVE_ATTRIBUTE", justification = "Preserve API compatibility.")
     public List<LockStepResource> extra = null;
 
     // it should be LockStep() - without params. But keeping this for backward compatibility

src/main/java/org/jenkins/plugins/lockableresources/LockStepResource.java

@@ -3,6 +3,7 @@
 import edu.umd.cs.findbugs.annotations.CheckForNull;
 import edu.umd.cs.findbugs.annotations.NonNull;
 import edu.umd.cs.findbugs.annotations.Nullable;
+import edu.umd.cs.findbugs.annotations.SuppressFBWarnings;
 import hudson.Extension;
 import hudson.Util;
 import hudson.model.AbstractDescribableImpl;
@@ -28,8 +29,10 @@ public class LockStepResource extends AbstractDescribableImpl<LockStepResource>
     public String resource = null;
 
     @CheckForNull
+    @SuppressFBWarnings(value = "PA_PUBLIC_PRIMITIVE_ATTRIBUTE", justification = "Preserve API compatibility.")
     public String label = null;
 
+    @SuppressFBWarnings(value = "PA_PUBLIC_PRIMITIVE_ATTRIBUTE", justification = "Preserve API compatibility.")
     public int quantity = 0;
 
     LockStepResource(@Nullable String resource, @Nullable String label, int quantity) {