Adds constructors for RtNetlinkAddressMessage and StructIfaddrMsg

Adds constructors for RtNetlinkAddressMessage and StructIfaddrMsg to
make it possible to directly construct RtNetlinkAddressMessage in the
test cases.

Bug: 267980538
Test: m
Change-Id: I21bf0cbef888495dc9a165a0fe6d5b39135e4c18
diff --git a/staticlibs/device/com/android/net/module/util/netlink/RtNetlinkAddressMessage.java b/staticlibs/device/com/android/net/module/util/netlink/RtNetlinkAddressMessage.java
index c07cec0..31c3a2e 100644
--- a/staticlibs/device/com/android/net/module/util/netlink/RtNetlinkAddressMessage.java
+++ b/staticlibs/device/com/android/net/module/util/netlink/RtNetlinkAddressMessage.java
@@ -58,12 +58,20 @@
     @Nullable
     private StructIfacacheInfo mIfacacheInfo;
 
-    private RtNetlinkAddressMessage(@NonNull StructNlMsgHdr header) {
+    @VisibleForTesting
+    public RtNetlinkAddressMessage(@NonNull final StructNlMsgHdr header,
+            @NonNull final StructIfaddrMsg ifaddrMsg,
+            @NonNull final InetAddress ipAddress,
+            @Nullable final StructIfacacheInfo structIfacacheInfo,
+            int flags) {
         super(header);
-        mIfaddrmsg = null;
-        mIpAddress = null;
-        mIfacacheInfo = null;
-        mFlags = 0;
+        mIfaddrmsg = ifaddrMsg;
+        mIpAddress = ipAddress;
+        mIfacacheInfo = structIfacacheInfo;
+        mFlags = flags;
+    }
+    private RtNetlinkAddressMessage(@NonNull StructNlMsgHdr header) {
+        this(header, null, null, null, 0);
     }
 
     public int getFlags() {
diff --git a/staticlibs/device/com/android/net/module/util/netlink/StructIfaddrMsg.java b/staticlibs/device/com/android/net/module/util/netlink/StructIfaddrMsg.java
index 9196feb..2802726 100644
--- a/staticlibs/device/com/android/net/module/util/netlink/StructIfaddrMsg.java
+++ b/staticlibs/device/com/android/net/module/util/netlink/StructIfaddrMsg.java
@@ -18,6 +18,7 @@
 
 import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
+import androidx.annotation.VisibleForTesting;
 
 import com.android.net.module.util.Struct;
 import com.android.net.module.util.Struct.Field;
@@ -49,7 +50,8 @@
     @Field(order = 4, type = Type.S32)
     public final int index;
 
-    StructIfaddrMsg(short family, short prefixLen, short flags, short scope, int index) {
+    @VisibleForTesting
+    public StructIfaddrMsg(short family, short prefixLen, short flags, short scope, int index) {
         this.family = family;
         this.prefixLen = prefixLen;
         this.flags = flags;