AccountExternalIdInfo: Implement hashCode alongside equals

Change-Id: I5f88bd25dde7a9fb8d429a2ef4fad2f104de223a
diff --git a/gerrit-extension-api/src/main/java/com/google/gerrit/extensions/common/AccountExternalIdInfo.java b/gerrit-extension-api/src/main/java/com/google/gerrit/extensions/common/AccountExternalIdInfo.java
index 39f4847..3bcf387 100644
--- a/gerrit-extension-api/src/main/java/com/google/gerrit/extensions/common/AccountExternalIdInfo.java
+++ b/gerrit-extension-api/src/main/java/com/google/gerrit/extensions/common/AccountExternalIdInfo.java
@@ -44,4 +44,9 @@
     }
     return false;
   }
+
+  @Override
+  public int hashCode() {
+    return Objects.hash(identity, emailAddress, trusted, canDelete);
+  }
 }