google-java-format: Reflow long strings does not give same output

The following input

```java
public class Test {
private String longString = "asdf asdf asdf asdf asdfasdfasdfasdfasdfasdfasdfasdfasdfasdfasdfasdfasdfasdfasdfasdfasdfasdfasdfasdfasdfasdfasdfasdfasdfasdfasdfa";
}
```

Becomes

```java
public class Test {
private String longString =
"asdf asdf asdf asdf"
+ " asdfasdfasdfasdfasdfasdfasdfasdfasdfasdfasdfasdfasdfasdfasdfasdfasdfasdfasdfasdfasdfasdfasdfasdfasdfasdfasdfa";
}
```

Using google-java-format AOSP

When using the gradle task `./gradlew spotlessApply` this becomes

```java
public class Test {
private String longString =
"asdf asdf asdf asdf"
+ " asdfasdfasdfasdfasdfasdfasdfasdfasdfasdfasdfasdfasdfasdfasdfasdfasdfasdfasdfasdfasdfasdfasdfasdfasdfasdfasdfa";
}
```

Gradle version: 8.10.2
Spotless version: 6.25.0 and 7.0.0.BETA4 (same result)
Operating system: macOS 15.0.1

Spotless config:
```kotlin
extensions.configure {
java {
googleJavaFormat("1.24.0").aosp().reorderImports(true)
}
}
```

Reproduce the discrepancy with ./gradlew spotlessApply using google-java-format 1.24.0 in AOSP mode and the shown Spotless configuration. Compare its output with direct google-java-format output for the long-string example; done means both produce the same indentation and formatting.

Scritto dal modello di indicizzazione a partire dal testo della issue.