AArch64: Use of long for pointers in PropertyValuesHolder

Long is used in PropertyValuesHolder class to store native pointers
as they can be 64-bit. Note that jmethodID, a pointer to structures,
is also carried in long rather than int to support 64-bit system.

Signed-off-by: Marcus Oakland <marcus.oakland@arm.com>
Signed-off-by: Ashok Bhat <ashok.bhat@arm.com>

(cherry picked from commit 0141e884)

Change-Id: I80408a7227427732db0d8b4c960bcb849b7c8060