[Build] Add a property to disable usernames obfuscation for build scans

The property is `kotlin.build.scan.obfuscate.username`

repo/gradle-settings-conventions/gradle-enterprise/src/main/kotlin/gradle-enterprise.settings.gradle.kts

@@ -6,7 +6,6 @@ plugins {
 val buildProperties = getKotlinBuildPropertiesForSettings(settings)
 
 val buildScanServer = buildProperties.buildScanServer
-val isTeamCity = buildProperties.isTeamcityBuild
 
 if (buildProperties.buildScanServer != null) {
     plugins.apply("com.gradle.common-custom-user-data-gradle-plugin")
@@ -29,11 +28,19 @@ gradleEnterprise {
             termsOfServiceAgree = "yes"
         }
 
-        val username = if (isTeamCity) "TeamCity" else "concealed"
+        val overridenName = (buildProperties.getOrNull("kotlin.build.scan.username") as? String)?.trim()
+        val isTeamCity = buildProperties.isTeamcityBuild
         obfuscation {
             ipAddresses { _ -> listOf("0.0.0.0") }
             hostname { _ -> "concealed" }
-            username { _ -> username }
+            username { originalUsername ->
+                when {
+                    isTeamCity -> "TeamCity"
+                    overridenName == null || overridenName.isEmpty() -> "concealed"
+                    overridenName == "<default>" -> originalUsername
+                    else -> overridenName
+                }
+            }
         }
     }
 }