Add span name for ECS flight config fetch telemetry, Fixes AB#3422868 (#2806)

Main PR AzureAD/ad-accounts-for-android#3271 

Fixes
[AB#3422868](https://identitydivision.visualstudio.com/fac9d424-53d2-45c0-91b5-ef6ba7a6bf26/_workitems/edit/3422868)

Author: mohitc1

common4j/src/main/com/microsoft/identity/common/java/opentelemetry/SpanName.java

@@ -74,5 +74,10 @@ public enum SpanName {
     ProcessWebCpAuthorizeUrlRedirect,
     PasskeyWebListener,
     PersistToStorageAsync,
-    InstallCertOnWpj
+    InstallCertOnWpj,
+
+    /**
+     * Span name for fetching initial ECS flight configurations.
+     */
+    EcsFlightsFetchConfigs
 }