DataDrivenFormatTest/TestConsistentPivot will fail after April 30, 2019

Some test cases in DataDriveFormatTest/TestConsisntePivot use Japanese calendar and the expected results may change depending on time of execution.

For example:
```
{
"en_US@calendar=japanese",
"",
"PATTERN=G y",
"YEAR=8",
"Heisei 8"
},
```
This test cases expects year 8 is formatted as "Heisei 8". The expected output before May 1, 2019 is "Heisei 8", but it will be "Reiwa 8" after that.

I propose to comment out these test cases depending on current Japanese era, then discuss whether we want to restore the test case replacing "Heisei" with "Reiwa" after transition period, or add a separate test case checking the same thing, but dynamically.