Flat-map registry lock emails to avoid unclean errors in bad situations (#525)

* Flat map to avoid unclean errors in bad situations

Also properly reflect that for admins, we will use their user email

* Make MS's GAE user ID a public static field

core/src/main/java/google/registry/ui/server/registrar/RegistryLockGetAction.java

@@ -159,9 +159,10 @@ public final class RegistryLockGetAction implements JsonGetAction {
         isAdmin || contactOptional.map(RegistrarContact::isRegistryLockAllowed).orElse(false);
     // Use the contact's registry lock email if it's present, else use the login email (for admins)
     String relevantEmail =
-        contactOptional
-            .map(contact -> contact.getRegistryLockEmailAddress().get())
-            .orElse(user.getEmail());
+        isAdmin
+            ? user.getEmail()
+            // if the contact isn't present, we shouldn't display the email anyway so empty is fine
+            : contactOptional.flatMap(RegistrarContact::getRegistryLockEmailAddress).orElse("");
     return ImmutableMap.of(
         LOCK_ENABLED_FOR_CONTACT_PARAM,
         isRegistryLockAllowed,

core/src/test/java/google/registry/server/RegistryTestServerMain.java

@@ -62,7 +62,7 @@ public final class RegistryTestServerMain {
   @Parameter(
       names = "--login_user_id",
       description = "GAE User ID for App Engine Local User Service.")
-  private String loginUserId = AppEngineRule.THE_REGISTRAR_GAE_USER_ID;
+  private String loginUserId = AppEngineRule.MARLA_SINGER_GAE_USER_ID;
 
   @Parameter(
       names = "--login_is_admin",

core/src/test/java/google/registry/testing/AppEngineRule.java

@@ -71,6 +71,7 @@ public final class AppEngineRule extends ExternalResource {
 
   public static final String NEW_REGISTRAR_GAE_USER_ID = "666";
   public static final String THE_REGISTRAR_GAE_USER_ID = "31337";
+  public static final String MARLA_SINGER_GAE_USER_ID = "12345";
 
   /**
    * The GAE testing library requires queue.xml to be a file, not a resource in a jar, so we read it
@@ -250,7 +251,7 @@ public final class AppEngineRule extends ExternalResource {
         .setRegistryLockEmailAddress("Marla.Singer.RegistryLock@crr.com")
         .setPhoneNumber("+1.2128675309")
         .setTypes(ImmutableSet.of(RegistrarContact.Type.TECH))
-        .setGaeUserId("12345")
+        .setGaeUserId(MARLA_SINGER_GAE_USER_ID)
         .setAllowedToSetRegistryLockPassword(true)
         .setRegistryLockPassword("hi")
         .build();

core/src/test/java/google/registry/ui/server/registrar/RegistryLockGetActionTest.java

@@ -304,7 +304,7 @@ public final class RegistryLockGetActionTest {
                     "lockEnabledForContact",
                     true,
                     "email",
-                    "Marla.Singer.RegistryLock@crr.com",
+                    "Marla.Singer@crr.com",
                     "clientId",
                     "TheRegistrar",
                     "locks",