[LANG-1448] Fix invalid Java examples in StringUtils.containsOnly Javadoc

[kamGP92]

This PR fixes the invalid Java examples in Javadoc of StringUtils.containsOnly.
The old examples were non-compilable (like 'abab', 'abc').

Updated the

 block to use correct char arguments for the varargs signature:

StringUtils.containsOnly( "abab", 'a', 'b', 'c') = true

No functional changes; this only updates documentation.

[garydgregory]

-1: This PR contains a change to a method that doesn't match its signature and should not be changed.

[kamGP92]

-1: This PR contains a change to a method that doesn't match its signature and should not be changed.

Thanks for pointing that out.
I've updated the examples to follow the same pseudo-code notation used by containsAny , keeping the documentation style consistent across the class.

[garydgregory]

Hello @kamGP92

Please rebase on git master. I believe this PR is no longer necessary.

Tracking Jira: LANG-1448

[kamGP92]

Hello @kamGP92

Please rebase on git master. I believe this PR is no longer necessary.

Tracking Jira: LANG-1448

Rebased on current master
The issue appears to be resolved upstream, so this PR can be closed.
Thanks for the review.