Merge "Make vendor_ramdisk_available." am: ffa20c359b am: b0c28db5b4 am: 2d722eef75 am: c4fb2abfc7

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

Change-Id: Ica244623040b6bfe27035580dc4f0bd23169320a