Merge "Modify the comment of getPrivateDnsMode" am: f87b8a02a7 am: 45db4ff3e3 am: afcec9cbfe

Original change: https://android-review.googlesource.com/c/platform/frameworks/base/+/1640143

Change-Id: I60147e1c828e5d82556e58b67b8f138f63228e8f