CheckStyle attempted upgrade (8.36.2 -->> 8.41.1) summons a pack of 'Indentation' errors

^{Prologue: https://github.com/apache/kafka/pull/10656#issuecomment-836071563}

Scenario:

• bump CheckStyle to a more recent version (8.36.2 -->> 8.41.1)
• introduce (temporarily !) maxErrors CheckStyle property (in order to count errors)
• execute gradle command: ./gradlew checkstyleMain checkstyleTest
• around 50 of 'Indentation' CheckStyle errors (across 18 source code files) are shown

Note: there were some changes related to indentation between CheckStyle 8.36.2 and 8.41.1: https://checkstyle.sourceforge.io/releasenotes.html#Release_8.41.1

What can be done (options):

1. relax CheckStyle 'Indentation' rules (if possible)
2. comply with new CheckStyle 'Indentation' rules (and change/fix indentation fir these source code files)
3. there are some slim chances that this is a some kind of CheckStyle regression (maybe similar to this one: https://github.com/checkstyle/checkstyle/issues/9341). This should be checked with CheckStyle team.