Fix bad indentation when copy-paste to trimIndent()

#KT-33888 Fixed

idea/testData/copyPaste/plainTextLiteral/TrimIndent3.expected.kt

@@ -0,0 +1,4 @@
+val ti = """
+    fun indented() {
+    }
+""".trimIndent()

idea/testData/copyPaste/plainTextLiteral/TrimIndent3.kt

@@ -0,0 +1,3 @@
+val ti = """
+    <caret>
+""".trimIndent()

idea/testData/copyPaste/plainTextLiteral/TrimIndent3.txt

@@ -0,0 +1,2 @@
+fun indented() {
+    }