Address comments on NetworkStack AIDL v6

Address issues found during AIDL review:
 - Rename clientAddr to singleClientAddr
 - Do not use a ParcelableBundle for notifyNetworkTested or
   notifyDataStallSuspected; instead use AIDL parcelables for stronger
   backwards compatibility guarantees.

Test: atest NetworkMonitorTest ConnectivityServiceTest
      ConnectivityServiceIntegrationTest, manual
Bug: 153500847
Change-Id: Id9b71784e5f6294d203230e57737979e063ff0f8
diff --git a/Tethering/src/android/net/dhcp/DhcpServingParamsParcelExt.java b/Tethering/src/android/net/dhcp/DhcpServingParamsParcelExt.java
index 82a26be..4f8ad8a 100644
--- a/Tethering/src/android/net/dhcp/DhcpServingParamsParcelExt.java
+++ b/Tethering/src/android/net/dhcp/DhcpServingParamsParcelExt.java
@@ -169,7 +169,7 @@
      * <p>If not set, the default value is null.
      */
     public DhcpServingParamsParcelExt setSingleClientAddr(@Nullable Inet4Address clientAddr) {
-        this.clientAddr = clientAddr == null ? 0 : inet4AddressToIntHTH(clientAddr);
+        this.singleClientAddr = clientAddr == null ? 0 : inet4AddressToIntHTH(clientAddr);
         return this;
     }