RFR: 8299513: Clean up java.io [v9]

[Per Minborg]

On Wed, 11 Jan 2023 15:31:22 GMT, Per Minborg <pminborg at openjdk.org> wrote:

>> Code in java.io contains many legacy constructs and semantics not recommended including: 
>> 
>> * C-style array declaration 
>> * Unnecessary visibility 
>> * Redundant keywords in interfaces (e.g. public, static) 
>> * Non-standard naming for constants 
>> * Javadoc typos 
>> * Missing final declaration 
>> 
>> These should be fixed as a sanity effort.
>
> Per Minborg has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Convert field to static and revert copyright year

I am closing this PR. I will create separate PRs for different classes of fixes.

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PR: https://git.openjdk.org/jdk/pull/11848