Add binderLibTest_IPC_32

1) Add product_variables to binderLibTest because the test case
   CheckHandleZeroBinderHighBitsZeroCookie uses binder data structure.
2) Add binderLibTest_IPC_32 which always compiles the test program for
   32-bit binder.

Bug: 63307240
Bug: 62366937
Test: vts-tradefed run commandAndExit vts -m VtsKernelBinderTest
Change-Id: I40c738a039459fbfece9689012249ae7ea93df9d