Prepare api directory for udc mainline branch

udc-extended-api directory will be used only in udc mainline branch to
hide @FlaggedApi annotated api which is not supported in that branch

Copied api directories from udc mainline branch.

Bug: 299411828
Test: TH
Change-Id: I86023b1fb3e5f9b4b787a564303e6d2e60f74467
diff --git a/Tethering/common/TetheringLib/udc-extended-api/module-lib-current.txt b/Tethering/common/TetheringLib/udc-extended-api/module-lib-current.txt
new file mode 100644
index 0000000..460c216
--- /dev/null
+++ b/Tethering/common/TetheringLib/udc-extended-api/module-lib-current.txt
@@ -0,0 +1,50 @@
+// Signature format: 2.0
+package android.net {
+
+  public final class TetheringConstants {
+    field public static final String EXTRA_ADD_TETHER_TYPE = "extraAddTetherType";
+    field public static final String EXTRA_PROVISION_CALLBACK = "extraProvisionCallback";
+    field public static final String EXTRA_REM_TETHER_TYPE = "extraRemTetherType";
+    field public static final String EXTRA_RUN_PROVISION = "extraRunProvision";
+    field public static final String EXTRA_SET_ALARM = "extraSetAlarm";
+  }
+
+  public class TetheringManager {
+    ctor public TetheringManager(@NonNull android.content.Context, @NonNull java.util.function.Supplier<android.os.IBinder>);
+    method public int getLastTetherError(@NonNull String);
+    method @NonNull public String[] getTetherableBluetoothRegexs();
+    method @NonNull public String[] getTetherableIfaces();
+    method @NonNull public String[] getTetherableUsbRegexs();
+    method @NonNull public String[] getTetherableWifiRegexs();
+    method @NonNull public String[] getTetheredIfaces();
+    method @NonNull public String[] getTetheringErroredIfaces();
+    method public boolean isTetheringSupported();
+    method public boolean isTetheringSupported(@NonNull String);
+    method public void requestLatestTetheringEntitlementResult(int, @NonNull android.os.ResultReceiver, boolean);
+    method @Deprecated public int setUsbTethering(boolean);
+    method @RequiresPermission(anyOf={android.Manifest.permission.TETHER_PRIVILEGED, android.Manifest.permission.WRITE_SETTINGS}) public void startTethering(int, @NonNull java.util.concurrent.Executor, @NonNull android.net.TetheringManager.StartTetheringCallback);
+    method @Deprecated public int tether(@NonNull String);
+    method @Deprecated public int untether(@NonNull String);
+  }
+
+  public static interface TetheringManager.TetheredInterfaceCallback {
+    method public void onAvailable(@NonNull String);
+    method public void onUnavailable();
+  }
+
+  public static interface TetheringManager.TetheredInterfaceRequest {
+    method public void release();
+  }
+
+  public static interface TetheringManager.TetheringEventCallback {
+    method @Deprecated public default void onTetherableInterfaceRegexpsChanged(@NonNull android.net.TetheringManager.TetheringInterfaceRegexps);
+  }
+
+  @Deprecated public static class TetheringManager.TetheringInterfaceRegexps {
+    method @Deprecated @NonNull public java.util.List<java.lang.String> getTetherableBluetoothRegexs();
+    method @Deprecated @NonNull public java.util.List<java.lang.String> getTetherableUsbRegexs();
+    method @Deprecated @NonNull public java.util.List<java.lang.String> getTetherableWifiRegexs();
+  }
+
+}
+