Merge "Make vendor_ramdisk_available." am: ffa20c359b am: b0c28db5b4 am: 2d722eef75

Original change: https://android-review.googlesource.com/c/platform/external/libcxx/+/1469876

Change-Id: Id00e7b33890be2cc17a4beea382272e5f18d5732