Revert "MAC_OS_X_VERSION_MAX_ALLOWED is always >= 1080 now"

This reverts commit b02e958fa0bf7d062a5b8aff03d22325e3068feb.

Change-Id: Ia7bf904071ac93f31c999433c74369c56c74c470
Use MACOSX_SDK_VERSION instead of MAC_OS_X_VERSION_MAX_ALLOWED

Change-Id: If24adf787821b2f83a7ecf8806f4d36b9eb7dbdc