Java to Kotlin conversion: fixed a few bugs related to modifiers

#KT-4424 Fixed

j2k/tests/testData/ast/settings/openByDefault.kt

@@ -0,0 +1,34 @@
+// !openByDefault: true
+
+open class A() {
+    open fun foo1() {
+    }
+    private fun foo2() {
+    }
+    fun foo3() {
+    }
+}
+
+class B() {
+    fun foo() {
+    }
+}
+
+abstract class C() {
+    abstract fun foo()
+}
+
+trait I {
+    public fun foo()
+}
+
+open class D() : I {
+    override fun foo() {
+    }
+}
+
+enum class E {
+    fun foo(): Int {
+        return 0
+    }
+}

j2k/tests/testData/ast/trait/abstactInterface.kt

@@ -1 +1 @@
-abstract trait I
+trait I

j2k/tests/testData/ast/trait/interfaceWithFields.kt

@@ -1,7 +1,7 @@
 trait INode {
     class object {
-        val IN: String = "in"
-        val AT: String = "@"
-        val COMMA_WITH_SPACE: String = COMMA + SPACE
+        public val IN: String = "in"
+        public val AT: String = "@"
+        public val COMMA_WITH_SPACE: String = COMMA + SPACE
     }
 }

j2k/tests/testData/ast/trait/interfaceWithMethodDeclaration.kt

@@ -1,4 +1,4 @@
 trait INode {
-    fun getTag(): Tag
-    fun toKotlin(): String
+    public fun getTag(): Tag
+    public fun toKotlin(): String
 }