Convert to expression body: fixed type selection for public override

idea/testData/intentions/convertToExpressionBody/overridePublicFun.kt

@@ -0,0 +1,9 @@
+open class A {
+    public open fun foo(): String = ""
+}
+
+class B : A() {
+    public override fun <caret>foo(): String {
+        return "abc"
+    }
+}

idea/testData/intentions/convertToExpressionBody/overridePublicFun.kt.after

@@ -0,0 +1,7 @@
+open class A {
+    public open fun foo(): String = ""
+}
+
+class B : A() {
+    public override fun foo()<selection>: String</selection> = "abc"
+}