[ST02.1] Add TYPE_CNAME constant to DnsResolver am: 822ab28a9b am: e8be60a398

Original change: https://android-review.googlesource.com/c/platform/packages/modules/Connectivity/+/2164655

Change-Id: Ic678b6e9ba4b99db38c7a0d11fc144cb1ce4bc4d
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>