[ULC] Unify modifiers for RepeatableAnnotationContainer

All the other annotation classes has abstract modifier.
All nested interfaces has static modifiers.

This commit is not so important for compiler, but it is matter for IDE,
because when we load classes in IDE via
KtLightClassForDecompiledDeclaration -- there are Abstract and Static
on the Container class

compiler/testData/asJava/lightClasses/AnnotationRepeatable.java

@@ -7,7 +7,7 @@ public abstract @interface One /* simple.One*/ {
 
 @java.lang.annotation.Retention(value = java.lang.annotation.RetentionPolicy.RUNTIME)
 @kotlin.jvm.internal.RepeatableContainer()
-public @interface Container /* simple.One.Container*/ {
+public static abstract @interface Container /* simple.One.Container*/ {
   public abstract simple.One[] value();//  value()
 
 }}