Remove some unnecessary reflection now that the formatter only supports JDK 17

PiperOrigin-RevId: 699235273

Author: cushon

core/src/main/java/com/google/googlejavaformat/java/StringWrapper.java

@@ -45,7 +45,6 @@
 import com.sun.tools.javac.util.Position;
 import java.io.IOException;
 import java.io.UncheckedIOException;
-import java.lang.reflect.Method;
 import java.net.URI;
 import java.util.ArrayDeque;
 import java.util.ArrayList;
@@ -61,7 +60,6 @@
 import javax.tools.JavaFileObject;
 import javax.tools.SimpleJavaFileObject;
 import javax.tools.StandardLocation;
-import org.jspecify.annotations.Nullable;
 
 /** Wraps string literals that exceed the column limit. */
 public final class StringWrapper {
@@ -204,7 +202,7 @@ private void indentTextBlocks(
         // The first line of the text block is always """, and it does not affect incidental
         // whitespace.
         ImmutableList<String> initialLines = text.lines().collect(toImmutableList());
-        String stripped = stripIndent(initialLines.stream().skip(1).collect(joining(separator)));
+        String stripped = initialLines.stream().skip(1).collect(joining(separator)).stripIndent();
         ImmutableList<String> lines = stripped.lines().collect(toImmutableList());
         int deindent =
             getLast(initialLines).stripTrailing().length()
@@ -280,30 +278,6 @@ private void wrapLongStrings(
     }
   }
 
-  private static final Method STRIP_INDENT = getStripIndent();
-
-  private static @Nullable Method getStripIndent() {
-    if (Runtime.version().feature() < 15) {
-      return null;
-    }
-    try {
-      return String.class.getMethod("stripIndent");
-    } catch (NoSuchMethodException e) {
-      throw new LinkageError(e.getMessage(), e);
-    }
-  }
-
-  private static String stripIndent(String input) {
-    if (STRIP_INDENT == null) {
-      return input;
-    }
-    try {
-      return (String) STRIP_INDENT.invoke(input);
-    } catch (ReflectiveOperationException e) {
-      throw new LinkageError(e.getMessage(), e);
-    }
-  }
-
   /**
    * Returns the source text of the given string literal trees, excluding the leading and trailing
    * double-quotes and the `+` operator.