Minor changes to the LinkAddress API docs.

1. Rename getNetworkPrefixLength to getPrefixLength. Update all
   callers in frameworks/base and add a shim method and a TODO
   for the rest.
2. @hide isSameAddressAs. It doesn't add much, and it's just
   one-liner that callers can implement if they want.
3. Fix the alignment of the initial paragraph (<ul> should have
   been </ul>).
4. Remove the documentation that talks about creating
   LinkAddresses, since there's no public API for creating them.

With these changes I think LinkAddress is fine as a public API.

Bug: 15142362
Change-Id: Iaf3b1db577745bb68a9e1dd7f96d666dd3f3ec7c
diff --git a/services/core/java/com/android/server/net/IpConfigStore.java b/services/core/java/com/android/server/net/IpConfigStore.java
index 35bc6ec..907eeb2 100644
--- a/services/core/java/com/android/server/net/IpConfigStore.java
+++ b/services/core/java/com/android/server/net/IpConfigStore.java
@@ -81,7 +81,7 @@
                     for (LinkAddress linkAddr : linkProperties.getLinkAddresses()) {
                         out.writeUTF(LINK_ADDRESS_KEY);
                         out.writeUTF(linkAddr.getAddress().getHostAddress());
-                        out.writeInt(linkAddr.getNetworkPrefixLength());
+                        out.writeInt(linkAddr.getPrefixLength());
                     }
                     for (RouteInfo route : linkProperties.getRoutes()) {
                         out.writeUTF(GATEWAY_KEY);
@@ -89,7 +89,7 @@
                         if (dest != null) {
                             out.writeInt(1);
                             out.writeUTF(dest.getAddress().getHostAddress());
-                            out.writeInt(dest.getNetworkPrefixLength());
+                            out.writeInt(dest.getPrefixLength());
                         } else {
                             out.writeInt(0);
                         }