DateFormatSymbols: inappropriate era string "HeiseiZen" for Japanese locale

takeshi.asano@Japan 1997-03-13

Era strings for Japan, which DateFormatSymbols.getEras() retunrs,
was recently updated as:

"HeiseiZen" (actually in Japanese Kanji characters)
"Heisei" (actually in Japanese Kanji characters)

Current era in Japan is "Heisei".
But no such word "HeiseiZen".

I'm not sure about policy, how each locale should fill each elements
of era string array. So I cannot show clear suggested fix at this
point. Can each locale freely put its own era strings as much as it has?