Remove VcnStatusCallback#onEnteredSafemode().

This CL removes VcnStatusCallback#onEnteredSafeMode(). This method was
previously used to notify callbacks when their VCN entered Safe Mode.
However, this is not needed now that
VcnStatusCallback#onVcnStatusChanged(int) is defined.

Bug: 1597023
Test: atest FrameworksVcnTests
Change-Id: I8e47de9bf6763cd38025a552bee710673dddf843

core/java/android/net/vcn/IVcnStatusCallback.aidl

@@ -18,7 +18,6 @@ package android.net.vcn;
 
 /** @hide */
 oneway interface IVcnStatusCallback {
-    void onEnteredSafeMode();
     void onVcnStatusChanged(int statusCode);
     void onGatewayConnectionError(
             in int[] gatewayNetworkCapabilities,

core/java/android/net/vcn/VcnManager.java

@@ -427,20 +427,6 @@ public class VcnManager {
     public abstract static class VcnStatusCallback {
         private VcnStatusCallbackBinder mCbBinder;
 
-        /**
-         * Invoked when the VCN for this Callback's subscription group enters safe mode.
-         *
-         * <p>A VCN will be put into safe mode if any of the gateway connections were unable to
-         * establish a connection within a system-determined timeout (while underlying networks were
-         * available).
-         *
-         * @deprecated Removed in favor of {@link #onVcnStatusChanged(int)}. To be removed in a
-         *     followup patch.
-         * @hide
-         */
-        @Deprecated
-        public void onEnteredSafeMode() {}
-
         /**
          * Invoked when status of the VCN for this callback's subscription group changes.
          *
@@ -584,12 +570,6 @@ public class VcnManager {
             mCallback = callback;
         }
 
-        @Override
-        public void onEnteredSafeMode() {
-            Binder.withCleanCallingIdentity(
-                    () -> mExecutor.execute(() -> mCallback.onEnteredSafeMode()));
-        }
-
         @Override
         public void onVcnStatusChanged(@VcnStatusCode int statusCode) {
             Binder.withCleanCallingIdentity(

tests/vcn/java/android/net/vcn/VcnManagerTest.java

@@ -203,9 +203,6 @@ public class VcnManagerTest {
         IVcnStatusCallback cbBinder =
                 new VcnStatusCallbackBinder(INLINE_EXECUTOR, mMockStatusCallback);
 
-        cbBinder.onEnteredSafeMode();
-        verify(mMockStatusCallback).onEnteredSafeMode();
-
         cbBinder.onVcnStatusChanged(VCN_STATUS_CODE_ACTIVE);
         verify(mMockStatusCallback).onVcnStatusChanged(VCN_STATUS_CODE_ACTIVE);