Add explicit copy constructors and assign operators for some classes.

It should fix compilation errors that happen on some iOS bots saying
"definition of implicit copy assignment operator for 'Foo'
is deprecated because it has a user-declared copy constructor"

Bug: webrtc:11162
Change-Id: Ife3d1a800ed6a4cd08bdfd156cd0e320504ee8dd
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/161221
Reviewed-by: Patrik Höglund <phoglund@webrtc.org>
Commit-Queue: Artem Titov <titovartem@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#29984}

rtc_base/ip_address.h

@@ -137,6 +137,7 @@ class RTC_EXPORT InterfaceAddress : public IPAddress {
   InterfaceAddress(const in6_addr& ip6, int ipv6_flags)
       : IPAddress(ip6), ipv6_flags_(ipv6_flags) {}
 
+  InterfaceAddress(const InterfaceAddress& other) = default;
   const InterfaceAddress& operator=(const InterfaceAddress& other);
 
   bool operator==(const InterfaceAddress& other) const;