Fix various Error Prone errors that were found by the FOSS build

Most common:
- Unnecessary parentheses and operator precedence clarify (self-explanatory)
- Reference equality--there were a few instances of using == or != improperly
- Qualification of Builder (and similar) imports so that it's clear which type of Builder we're referring to
- Marking some immutable classes with @Immutable since EP desires that all enums be deeply immutable
- String.split() having "surprising behavior"

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=230971531

java/google/registry/rde/ContactResourceToXjcConverter.java

@@ -36,6 +36,7 @@ import google.registry.xjc.eppcom.XjcEppcomTrStatusType;
 import google.registry.xjc.rdecontact.XjcRdeContact;
 import google.registry.xjc.rdecontact.XjcRdeContactElement;
 import google.registry.xjc.rdecontact.XjcRdeContactTransferDataType;
+import java.util.Objects;
 import javax.annotation.CheckForNull;
 import javax.annotation.Nullable;
 
@@ -101,7 +102,7 @@ final class ContactResourceToXjcConverter {
     //       required before an automated response action will be taken by
     //       the registry.  For all other status types, the value identifies
     //       the date and time when the request was completed.
-    if (model.getTransferData() != TransferData.EMPTY) {
+    if (!Objects.equals(model.getTransferData(), TransferData.EMPTY)) {
       bean.setTrnData(convertTransferData(model.getTransferData()));
     }
 

java/google/registry/rde/RdeResourceType.java

@@ -17,12 +17,11 @@ package google.registry.rde;
 import static google.registry.model.rde.RdeMode.FULL;
 import static google.registry.model.rde.RdeMode.THIN;
 
+import com.google.common.collect.ImmutableSet;
 import com.google.common.collect.ImmutableSortedSet;
 import com.google.common.collect.Ordering;
 import google.registry.model.rde.RdeMode;
-import java.util.Collections;
 import java.util.EnumSet;
-import java.util.Set;
 
 /** Types of objects that get embedded in an escrow deposit. */
 public enum RdeResourceType {
@@ -34,11 +33,11 @@ public enum RdeResourceType {
   HEADER("urn:ietf:params:xml:ns:rdeHeader-1.0", EnumSet.of(FULL, THIN));
 
   private final String uri;
-  private final Set<RdeMode> modes;
+  private final ImmutableSet<RdeMode> modes;
 
   RdeResourceType(String uri, EnumSet<RdeMode> modes) {
     this.uri = uri;
-    this.modes = Collections.unmodifiableSet(modes);
+    this.modes = ImmutableSet.copyOf(modes);
   }
 
   /** Returns RDE XML schema URI specifying resource. */
@@ -47,7 +46,7 @@ public enum RdeResourceType {
   }
 
   /** Returns set indicating if resource is stored in BRDA thin deposits. */
-  public Set<RdeMode> getModes() {
+  public ImmutableSet<RdeMode> getModes() {
     return modes;
   }
 

java/google/registry/rde/RdeUploadUrl.java

@@ -164,8 +164,7 @@ final class RdeUploadUrl implements Comparable<RdeUploadUrl> {
   @Override
   public boolean equals(@Nullable Object object) {
     return object == this
-        || object instanceof RdeUploadUrl
-        && Objects.equals(uri, ((RdeUploadUrl) object).uri);
+        || (object instanceof RdeUploadUrl && Objects.equals(uri, ((RdeUploadUrl) object).uri));
   }
 
   /** @see java.net.URI#hashCode() */
@@ -200,9 +199,9 @@ final class RdeUploadUrl implements Comparable<RdeUploadUrl> {
     @Override
     public boolean equals(@Nullable Object object) {
       return object == this
-          || object instanceof Protocol
-          && port == ((Protocol) object).port
-          && Objects.equals(name, ((Protocol) object).name);
+          || (object instanceof Protocol
+              && port == ((Protocol) object).port
+              && Objects.equals(name, ((Protocol) object).name));
     }
 
     /** @see Object#hashCode() */