Release 6.1.0 - cherry pick of #3007 (#3011)

* 6.1.0 manifest updated. FirebaseInAppMessaging bumped to 0.14.1

* Early return from sending analytics events in instance ID is nil (#3007)

Firebase/InAppMessaging/Analytics/FIRIAMClearcutLogger.m

@@ -149,6 +149,13 @@ - (void)logAnalyticsEventForType:(FIRIAMAnalyticsLogEventType)eventType
     eventTimeInMs = @((long)nowInMs);
   }
 
+  if (!iid) {
+    FIRLogWarning(kFIRLoggerInAppMessaging, @"I-IAM210009",
+                  @"Instance ID is nil, event %ld for campaign ID %@ will not be sent",
+                  (long)eventType, campaignID);
+    return;
+  }
+
   NSString *sourceExtensionJsonString =
       [self constructSourceExtensionJsonForClearcutWithEventType:eventType
                                                    forCampaignID:campaignID

FirebaseInAppMessaging.podspec

@@ -1,6 +1,6 @@
 Pod::Spec.new do |s|
   s.name             = 'FirebaseInAppMessaging'
-  s.version          = '0.14.0'
+  s.version          = '0.14.1'
   s.summary          = 'Firebase In-App Messaging for iOS'
 
   s.description      = <<-DESC

Releases/Manifests/6.1.0.json

@@ -3,6 +3,7 @@
   "FirebaseCore":"6.0.1",
   "FirebaseFirestore":"1.3.1",
   "FirebaseFunctions":"2.5.1",
+  "FirebaseInAppMessaging":"0.14.1",
   "FirebaseInstanceID":"4.1.0",
   "FirebaseMessaging":"4.0.1",
   "FirebaseStorage":"3.2.1"