Minor. Use more granular assertion levels in assertion tests

compiler/testData/codegen/box/assert/jvm/interfaceAssertionsEnabled.kt

@@ -3,6 +3,8 @@
 // KOTLIN_CONFIGURATION_FLAGS: ASSERTIONS_MODE=jvm
 // WITH_RUNTIME
 
+package interfaceAssertionsEnabled
+
 interface Checker {
     fun checkTrue(): Boolean {
         var hit = false
@@ -39,8 +41,8 @@ class Dummy
 
 fun enableAssertions(): Checker {
     val loader = Dummy::class.java.classLoader
-    loader.setDefaultAssertionStatus(true)
-    val c = loader.loadClass("ShouldBeEnabled")
+    loader.setPackageAssertionStatus("interfaceAssertionsEnabled", true)
+    val c = loader.loadClass("interfaceAssertionsEnabled.ShouldBeEnabled")
     return c.newInstance() as Checker
 }