add support for LOCAL_MODULE_PATH_32 and LOCAL_MODULE_PATH_64

Some executables will need to be built for both 32-bit and 64-bit.
For tests, it will be convienient to keep the name of the executable
the same, but install them in a different location.  Add
LOCAL_MODULE_PATH_32 and LOCAL_MODULE_PATH_64 to allow a module
to specify different paths for 32-bit and 64-bit executables.

Change-Id: I3be830e899c6d485fe55c25c66b20b3fe64c795e