Add NetworkUtils utilities to SystemApi

attach*Filter and addArpEntry are necessary for the NetworkStack but are
only usable for apps that have system permissions.
Also includes system API for IpPrefix, LinkAddress, LinkProperties,
Network, and static modifier in ApfCapabilities that were missed in
previous CLs.

Test: Builds, flashed, WiFi works
Bug: 112869080
Change-Id: If141ae6a2f9145f5af64ba002ca44938f39b90a9
diff --git a/core/java/android/net/apf/ApfCapabilities.java b/core/java/android/net/apf/ApfCapabilities.java
index baf5585..e09fa8f 100644
--- a/core/java/android/net/apf/ApfCapabilities.java
+++ b/core/java/android/net/apf/ApfCapabilities.java
@@ -81,14 +81,14 @@
     /**
      * @return Whether the APF Filter in the device should filter out IEEE 802.3 Frames.
      */
-    public boolean getApfDrop8023Frames(Context context) {
+    public static boolean getApfDrop8023Frames(Context context) {
         return context.getResources().getBoolean(R.bool.config_apfDrop802_3Frames);
     }
 
     /**
      * @return An array of blacklisted EtherType, packets with EtherTypes within it will be dropped.
      */
-    public int[] getApfEthTypeBlackList(Context context) {
+    public static int[] getApfEthTypeBlackList(Context context) {
         return context.getResources().getIntArray(R.array.config_apfEthTypeBlackList);
     }
 }