pgsql: Add expected isolationtester output when prepared xacts are disa

Add expected isolationtester output when prepared xacts are disabled

This was deemed unnecessary initially but in later discussion it was
agreed otherwise.

Original file from Kevin Grittner, allegedly from Dan Ports.
I had to clean up whitespace a bit per changes from Heikki.

Branch
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master

Details
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http://git.postgresql.org/pg/commitdiff/28190bacfd4657954c2cd594cc1c3e6b691538b9

Modified Files
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.../isolation/expected/prepared-transactions_1.out |41529 ++++++++++++++++++++
src/test/isolation/isolation_schedule              |    4 -
2 files changed, 41529 insertions(+), 4 deletions(-)