This partially reverts Ic6bb5e66. It made private some methods in
ReceivePack that were protected before. At least two of those methods
(#init and #receivePackAndCheckConnectivity) are used by out-of-tree
subclasses for tracing and testing.
Make ReceivePack#init() and ReceivePack#receivePackAndCheckConnectivity
protected again to allow tracing and testing.
Change-Id: I7ff22c091fbfc2d94009c449d58e7c5ac9f4f759 Signed-off-by: Ivan Frade <ifrade@google.com>