Unhide NetworkRequest API which use legacy type

Bug: 144753389
Test: -build, flash, boot
      -atest TetheringTests

Change-Id: I349da06769e9ffcee6bb42f51ab454e0ef774fb3
Merged-In: I349da06769e9ffcee6bb42f51ab454e0ef774fb3
diff --git a/api/system-current.txt b/api/system-current.txt
index 7d9cf5f..766512b 100755
--- a/api/system-current.txt
+++ b/api/system-current.txt
@@ -4297,6 +4297,7 @@
     method @RequiresPermission(anyOf={android.Manifest.permission.TETHER_PRIVILEGED, android.Manifest.permission.WRITE_SETTINGS}) public boolean isTetheringSupported();
     method @RequiresPermission(android.Manifest.permission.NETWORK_FACTORY) public int registerNetworkProvider(@NonNull android.net.NetworkProvider);
     method @RequiresPermission(android.Manifest.permission.TETHER_PRIVILEGED) public void registerTetheringEventCallback(@NonNull java.util.concurrent.Executor, @NonNull android.net.ConnectivityManager.OnTetheringEventCallback);
+    method @Deprecated public void requestNetwork(@NonNull android.net.NetworkRequest, @NonNull android.net.ConnectivityManager.NetworkCallback, int, int, @NonNull android.os.Handler);
     method @RequiresPermission(anyOf={"android.permission.NETWORK_SETTINGS", android.Manifest.permission.NETWORK_SETUP_WIZARD, "android.permission.NETWORK_STACK"}) public void setAirplaneMode(boolean);
     method @RequiresPermission(anyOf={android.net.NetworkStack.PERMISSION_MAINLINE_NETWORK_STACK, "android.permission.NETWORK_STACK"}) public boolean shouldAvoidBadWifi();
     method @RequiresPermission(android.net.NetworkStack.PERMISSION_MAINLINE_NETWORK_STACK) public void startCaptivePortalApp(@NonNull android.net.Network, @NonNull android.os.Bundle);
diff --git a/core/java/android/net/ConnectivityManager.java b/core/java/android/net/ConnectivityManager.java
index 3c85649..6eee332 100644
--- a/core/java/android/net/ConnectivityManager.java
+++ b/core/java/android/net/ConnectivityManager.java
@@ -3622,14 +3622,26 @@
     /**
      * Helper function to request a network with a particular legacy type.
      *
-     * This is temporarily public @hide so it can be called by system code that uses the
-     * NetworkRequest API to request networks but relies on CONNECTIVITY_ACTION broadcasts for
-     * instead network notifications.
+     * @deprecated This is temporarily public for tethering to backwards compatibility that uses
+     * the NetworkRequest API to request networks with legacy type and relies on
+     * CONNECTIVITY_ACTION broadcasts instead of NetworkCallbacks. New caller should use
+     * {@link #requestNetwork(NetworkRequest, NetworkCallback, Handler)} instead.
      *
      * TODO: update said system code to rely on NetworkCallbacks and make this method private.
+
+     * @param request {@link NetworkRequest} describing this request.
+     * @param networkCallback The {@link NetworkCallback} to be utilized for this request. Note
+     *                        the callback must not be shared - it uniquely specifies this request.
+     * @param timeoutMs The time in milliseconds to attempt looking for a suitable network
+     *                  before {@link NetworkCallback#onUnavailable()} is called. The timeout must
+     *                  be a positive value (i.e. >0).
+     * @param legacyType to specify the network type(#TYPE_*).
+     * @param handler {@link Handler} to specify the thread upon which the callback will be invoked.
      *
      * @hide
      */
+    @SystemApi
+    @Deprecated
     public void requestNetwork(@NonNull NetworkRequest request,
             @NonNull NetworkCallback networkCallback, int timeoutMs, int legacyType,
             @NonNull Handler handler) {