[Binder] memory init to avoid valgrind warnings

To avoid a valgrind warning, it is necessary to initialize the
allocated memory in Parcel.cpp This initialization should
avoid also an unpredictable behaviour because 0 is more
appropriate value that a random value from heap.
The issue has been found by valgrind when testing of mediaserver.

Change-Id: I2eb3e3ec7933553256054119019f6ccea6e17fea
Author: Andrei V. FOMITCHEV <andreix.fomitchev@intel.com>
Signed-off-by: Andrei V. FOMITCHEV <andreix.fomitchev@intel.com>
Signed-off-by: Jin Wei <wei.a.jin@intel.com>
Signed-off-by: Shuo Gao <shuo.gao@intel.com>
Signed-off-by: Bruce Beare <bruce.j.beare@intel.com>
Signed-off-by: Jack Ren <jack.ren@intel.com>
Author-tracking-BZ: 61459