Incorrect comment indentation inside switch statements

[Zopsss]

Detected at @checkstyle: checkstyle/checkstyle#15521 (comment)

We were working on improving Checkstyle's test cases for google style guide. We used google-java-format tool to format the input file and used google_checks.xml against it to ensure that we're following every rules. We had a case like:

    switch (a) {
      // comment
      case 1:
      default:
    }

formatter formatted it to something like:

    switch (a) {
        // comment
      case 1:
      default:
    }

the indentation for // comment increased, our test started failing and the violation message was:

764:9: Comment has incorrect indentation level 8, expected is 6, indentation should be the same level as line 765.

We faced this problem at 3 places in our input file, here's the full test result: checkstyle/checkstyle#15521 (comment)

Based on 4.8.4.1 Indentation & 4.2 Block indentation: +2 spaces, the content should be increased by 2 spaces but formatter increased the indentation by 4 spaces.

[cushon]

This is a duplicate of #1127, which is fixed at head and will be included in the next release