Fix class name for test suite descriptor.

Issue #KT-36725 Fixed
Issue #KT-36716 Fixed
Issue #KT-36726 Fixed

libraries/tools/kotlin-gradle-plugin/src/main/kotlin/org/jetbrains/kotlin/gradle/internal/testing/TCServiceMessagesClient.kt

@@ -432,6 +432,7 @@ internal open class TCServiceMessagesClient(
 
             descriptor = object : DefaultTestSuiteDescriptor(id, fullName) {
                 override fun getDisplayName(): String = fullNameWithoutRoot
+                override fun getClassName(): String? = fullNameWithoutRoot
                 override fun getOwnerBuildOperationId(): Any? = rootOperationId
                 override fun getParent(): TestDescriptorInternal = reportingParent.descriptor
                 override fun toString(): String = displayName