[Minor] Fix a typo of type parameter in JavaUtils.scala

In JavaUtils.scala, thare is a typo of type parameter. In addition, the type information is removed at the time of compile by erasure.

This issue is really minor so I don't  file in JIRA.
I thought it should be `A` but the type parameter at the position is no mean because the erasure removes type information at the time of compile.
Even though, should we place `A` for readability?