Merge "Split MOUNT_FLAG_VISIBLE into MOUNT_FLAG_VISIBLE_FOR_{READ, WRITE}" am: bddb449182 am: 6e9d37542f am: b43b71a2bc

Original change: https://android-review.googlesource.com/c/platform/system/vold/+/1891635

Change-Id: I9425ea87c9c57ba9ac7dcc4376cf86f931557d00