Use with_dexpreopt macro for zygote execute permissions.

When WITH_DEXPREOPT is set, the zygote does not need to execute
dalvikcache_data_file objects.

Bug: 32970029
Test: Add policy line inside macro, build with and without WITH_DEXPREOPT.
Test: HiKey builds, boots, no zygote denials.
Change-Id: I4dace93e8044267232f0f26cfe427fc250d351fb