UAST: correct processing of string literals in string literals (KT-20990)

plugins/uast-kotlin/src/org/jetbrains/uast/kotlin/KotlinAbstractUElement.kt

@@ -57,10 +57,10 @@ abstract class KotlinAbstractUElement(private val givenParent: UElement?) : UEle
             parent = parent.parent
         }
 
-        if (parent is KtStringTemplateEntryWithExpression) {
+        if (parent is KtStringTemplateExpression && parent.entries.size == 1) {
             parent = parent.parent
         }
-        if ((parent is KtStringTemplateExpression && parent.entries.size == 1)) {
+        if (parent is KtStringTemplateEntryWithExpression) {
             parent = parent.parent
         }
         if (parent is KtWhenConditionWithExpression) {

plugins/uast-kotlin/testData/StringTemplate.kt

@@ -3,3 +3,5 @@ val bar = "ipsum"
 val baz = "dolor"
 
 val foobarbaz = "$foo $bar $baz"
+
+val case4 = "a ${"literal"} z"

plugins/uast-kotlin/testData/StringTemplate.log.txt

@@ -17,7 +17,14 @@ UFile (package = )
                 USimpleNameReferenceExpression (identifier = bar)
                 ULiteralExpression (value = " ")
                 USimpleNameReferenceExpression (identifier = baz)
+        UField (name = case4)
+            UAnnotation (fqName = org.jetbrains.annotations.NotNull)
+            UPolyadicExpression (operator = +)
+                ULiteralExpression (value = "a ")
+                ULiteralExpression (value = "literal")
+                ULiteralExpression (value = " z")
         UAnnotationMethod (name = getFoo)
         UAnnotationMethod (name = getBar)
         UAnnotationMethod (name = getBaz)
         UAnnotationMethod (name = getFoobarbaz)
+        UAnnotationMethod (name = getCase4)

plugins/uast-kotlin/testData/StringTemplate.render.txt

@@ -3,8 +3,10 @@ public final class StringTemplateKt {
     private static final var bar: java.lang.String = "ipsum"
     private static final var baz: java.lang.String = "dolor"
     private static final var foobarbaz: java.lang.String = foo + " " + bar + " " + baz
+    private static final var case4: java.lang.String = "a " + "literal" + " z"
     public static final fun getFoo() : java.lang.String = UastEmptyExpression
     public static final fun getBar() : java.lang.String = UastEmptyExpression
     public static final fun getBaz() : java.lang.String = UastEmptyExpression
     public static final fun getFoobarbaz() : java.lang.String = UastEmptyExpression
+    public static final fun getCase4() : java.lang.String = UastEmptyExpression
 }