Add "product_available" to product available modules am: 8b6fee83e3 am: 9515ce7a8f am: 581c91dc40

Original change: https://android-review.googlesource.com/c/platform/external/libcxx/+/1495836

Change-Id: I7b796533f5af32a00aca13050c658b9c19ccfcad