The fix for 4179055 to ActivationGroup.createGroup added a doPrivileged block
around loading the group implementation class. This doPrivileged block is
unnecessary. The thinking was that it was needed to load an activation
group implementation in a sun.* package. Instead, the sun.* class need not be
loaded explicitly; the group implementation Class object for sun.rmi.server.ActivationGroupImpl can simply be referred to directly in the
code. This code should be cleaned up (i.e., the doPrivileged block eliminated).

Minor note: the bug number in the comment above the doPrivileged block is
incorrect. It erroneously states the bug number as 4170955 instead of 4179055.