Fix TextIO.read() split with non-default delimiter

[Amar3tto]

Resolves #32251

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[Amar3tto]

assign set of reviewers

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[Abacn]

Could we preserve this existing line case. just add one more line to test *||**|, like

// complete delimiter
"Whether 'tis nobler in the mind to suffer |*",
// edge case: partial delimiter then complete delimiter
"The slings and arrows of outrageous fortune,*||**|"
// truncated delimiter
"Or to take arms against a sea of troubles,|"

[Amar3tto]

Run Java_GCP_IO_Direct PreCommit

[baeminbo]

Could you check #32251 (comment)? I think this PR cannot fix all the cases of the issue #32251.