Revert "K2/Java: add private enum constructor for MPP matching"

Review: https://jetbrains.team/p/kt/reviews/13368/timeline

This reverts commit 2cea2b9098.

Motivation:
KT-62961 was fixed independently by two different commits:
- ac3d8ad3ac
- 2cea2b9098

If possible, it's better not to introduce implicit declarations.
That's why it was agreed to keep
ac3d8ad3ac and revert
2cea2b9098

compiler/testData/loadJava/compiledJava/annotations/CustomAnnotation.fir.txt

@@ -14,8 +14,6 @@ public abstract interface CustomAnnotation : R|kotlin/Any| {
         public final static val entries: R|kotlin/enums/EnumEntries<test/CustomAnnotation.MyEnum>|
             public get(): R|kotlin/enums/EnumEntries<test/CustomAnnotation.MyEnum>|
 
-        private constructor(): R|test/CustomAnnotation.MyEnum|
-
     }
     @R|test/CustomAnnotation.MyAnnotation|(value = R|test/CustomAnnotation.MyEnum.ONE|) public open class MyTest : R|kotlin/Any| {
         public constructor(): R|test/CustomAnnotation.MyTest|