Add parceling for DhcpServingParams

Introduce a stable AIDL parcel class, DhcpServingParamsParcel, and
methods to convert to and from that class to DhcpServingParams.
This will be used to move DhcpServer to the NetworkStack app.

Test: atest FrameworksNetTests
Bug: b/112869080
Change-Id: I276b7affccb938059769c90a53f0f6beb26e6ede
diff --git a/Android.bp b/Android.bp
index 124f473..482b19d 100644
--- a/Android.bp
+++ b/Android.bp
@@ -825,6 +825,7 @@
     local_include_dir: "core/java",
     srcs: [
         "core/java/android/net/INetworkStackConnector.aidl",
+        "core/java/android/net/dhcp/DhcpServingParamsParcel.aidl",
     ],
     api_dir: "aidl/networkstack",
 }