Cleaned up generateTzData
Cleaned up generateTzData

- Gave it a list of inputs/outputs so it doesn't run unnecessarily.

- Gave it a description/group

rjhonsl/joda-time-android,ptornhult/joda-time-android,dlew/joda-time-android,dlew/joda-time-android,andyao/joda-time-android,andyao/joda-time-android,netfirms/joda-time-android,xfumihiro/joda-time-android,ptornhult/joda-time-android,xfumihiro/joda-time-android,netfirms/joda-time-android,lucasxas/joda-time-android,lucasxas/joda-time-android,rjhonsl/joda-time-android