Add @deprecated javadoc to JapaneseCalendar.CURRENT_ERA

@Deprecated annotation is not enough. Both annotation and javadoc
are needed for a deprecated Android API.

Change-Id: I6a7c380a3ddfffb397b295fd5b874385ec1a0b85
Fix: 77850660
Test: @deprecated javadoc is added after running the code gen script
2 files changed