[KT] Add multi-dollar string interpolation example to Strings.kt readable.

This language feature is available since Kotlin 2.2.

PiperOrigin-RevId: 888338909

Author: jDramaix

transpiler/javatests/com/google/j2cl/readable/kotlin/strings/Strings.kt

@@ -207,6 +207,15 @@ class Strings {
     s1 = (1 + 2).toString() + "s"
     s1 = "s" + 1 + 2
   }
+
+  fun testMultiDollarInterpolation() {
+    val name = "world"
+    val s1 = $$$"Hello $$$name, $$name, $name"
+    val s2 =
+      $$"""Hello $$name
+      $name literal
+      """
+  }
 }
 
 private class Foo {

transpiler/javatests/com/google/j2cl/readable/kotlin/strings/output_closure/Strings.impl.java.js.txt

@@ -68,6 +68,12 @@ class Strings extends j_l_Object {
   s1 = j_l_String.m_valueOf__java_lang_Object__java_lang_String(Integer.valueOf(1 + 2 | 0).toString()) + 's';
   s1 = 's' + 1 + 2;
  }
+ /** @final @nodts */
+ m_testMultiDollarInterpolation__void() {
+  let name = 'world';
+  let s1 = '' + 'Hello ' + j_l_String.m_valueOf__java_lang_Object__java_lang_String(name) + ', $$name, $name';
+  let s2 = '' + 'Hello ' + j_l_String.m_valueOf__java_lang_Object__java_lang_String(name) + '\n      $name literal\n      ';
+ }
  /** @nodts */
  static $clinit() {
   Strings.$clinit = () =>{};