Error formatting long string literal that contains "...\\t"

In version n1.24.0 of google-java-format_windows-x86-64.exe a long string literal that contains two backslashes followed by 't' results in an error.

Negative example:
```Java
String t =
"0123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789\\t";
```

Tool invocation and error message:
```
$ google-java-format_windows-x86-64.exe -r --skip-removing-unused-imports test\Test.java
Test.java:29:7: error: unclosed string literal
"0123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789\\t";
```

Positive example. This can be formatted.
```Java
String s = "01234567890123456789012345678901234567890123456789\\t";
```

Update: Using parameter `--skip-reflowing-long-strings` avoids this error!

使用 google-java-format_windows-x86-64.exe，透過 Test.java 中的長字串字面值重現報告，然後比較使用 --skip-reflowing-long-strings 時的行為。追蹤長字串重新排版路徑，並驗證不使用此替代方案時，有問題的字面值也能成功格式化。

由索引模型根據 Issue 內容生成。