Let tests enumerate all transports/capabilities.

This gives them a way to collect all included values without
resorting to manual probing of each newly added value.

Bug: 16207332
Test: atest com.android.cts.net.HostsideVpnTests
Change-Id: I35ca412512dc8515b44d5518e1ca4caa5bdc678f

core/java/android/net/NetworkCapabilities.java

@@ -18,6 +18,7 @@ package android.net;
 
 import android.annotation.IntDef;
 import android.annotation.SystemApi;
+import android.annotation.TestApi;
 import android.net.ConnectivityManager.NetworkCallback;
 import android.os.Parcel;
 import android.os.Parcelable;
@@ -427,6 +428,7 @@ public final class NetworkCapabilities implements Parcelable {
      * @return an array of capability values for this instance.
      * @hide
      */
+    @TestApi
     public @NetCapability int[] getCapabilities() {
         return BitUtils.unpackBits(mNetworkCapabilities);
     }
@@ -690,6 +692,7 @@ public final class NetworkCapabilities implements Parcelable {
      * @return an array of transport type values for this instance.
      * @hide
      */
+    @TestApi
     public @Transport int[] getTransportTypes() {
         return BitUtils.unpackBits(mTransportTypes);
     }