Revert "Revert "Unhide IpPrefix(InetAddress, int)""

This reverts commit 758ead6dd362f8b7c665603fb9d85038b3f72f27.

Reason for revert: Re-landing changes not related to postsubmit failure

Change-Id: I2f705549d85af4ba45dc294e0a86d757490b1cd7
diff --git a/framework/api/current.txt b/framework/api/current.txt
index c53f29a..a755234 100644
--- a/framework/api/current.txt
+++ b/framework/api/current.txt
@@ -206,6 +206,7 @@
   }
 
   public final class IpPrefix implements android.os.Parcelable {
+    ctor public IpPrefix(@NonNull java.net.InetAddress, @IntRange(from=0, to=128) int);
     method public boolean contains(@NonNull java.net.InetAddress);
     method public int describeContents();
     method @NonNull public java.net.InetAddress getAddress();
diff --git a/framework/api/system-current.txt b/framework/api/system-current.txt
index 7db8725..5337b38 100644
--- a/framework/api/system-current.txt
+++ b/framework/api/system-current.txt
@@ -131,7 +131,6 @@
   }
 
   public final class IpPrefix implements android.os.Parcelable {
-    ctor public IpPrefix(@NonNull java.net.InetAddress, @IntRange(from=0, to=128) int);
     ctor public IpPrefix(@NonNull String);
   }
 
diff --git a/framework/src/android/net/IpPrefix.java b/framework/src/android/net/IpPrefix.java
index bf4481a..c26a0b5 100644
--- a/framework/src/android/net/IpPrefix.java
+++ b/framework/src/android/net/IpPrefix.java
@@ -87,9 +87,7 @@
      *
      * @param address the IP address. Must be non-null.
      * @param prefixLength the prefix length. Must be >= 0 and <= (32 or 128) (IPv4 or IPv6).
-     * @hide
      */
-    @SystemApi
     public IpPrefix(@NonNull InetAddress address, @IntRange(from = 0, to = 128) int prefixLength) {
         // We don't reuse the (byte[], int) constructor because it calls clone() on the byte array,
         // which is unnecessary because getAddress() already returns a clone.
diff --git a/tests/common/java/android/net/IpPrefixTest.java b/tests/common/java/android/net/IpPrefixTest.java
index 50ecb42..f61c8c3 100644
--- a/tests/common/java/android/net/IpPrefixTest.java
+++ b/tests/common/java/android/net/IpPrefixTest.java
@@ -122,6 +122,9 @@
 
         p = new IpPrefix("[2001:db8::123]/64");
         assertEquals("2001:db8::/64", p.toString());
+
+        p = new IpPrefix(InetAddresses.parseNumericAddress("::128"), 64);
+        assertEquals("::/64", p.toString());
     }
 
     @Test