Handle onNullBinding

According to the docs, an onNullBinding requires the service to be
manually unbound

Test: A test NLS service that returns null from onBind; ensure that the ServiceRecord
does not appear in the bugreport when that app has NLS permission
Bug: 192475653

Change-Id: I784910865fa11a5f88c4e6821007564d3aea7ec9

services/core/java/com/android/server/notification/ManagedServices.java

diff --git a/services/core/java/com/android/server/notification/ManagedServices.java b/services/core/java/com/android/server/notification/ManagedServices.java
index bccc52f..ddaaa1e 100644
--- a/services/core/java/com/android/server/notification/ManagedServices.java
+++ b/services/core/java/com/android/server/notification/ManagedServices.java
@@ -1536,7 +1536,7 @@
                 @Override
                 public void onNullBinding(ComponentName name) {
                     Slog.v(TAG, "onNullBinding() called with: name = [" + name + "]");
-                    mServicesBound.remove(servicesBindingTag);
+                    mContext.unbindService(this);
                 }
             };
             if (!mContext.bindServiceAsUser(intent,

services/tests/uiservicestests/src/com/android/server/notification/ManagedServicesTest.java

diff --git a/services/tests/uiservicestests/src/com/android/server/notification/ManagedServicesTest.java b/services/tests/uiservicestests/src/com/android/server/notification/ManagedServicesTest.java
index f9663f2..987236c 100644
--- a/services/tests/uiservicestests/src/com/android/server/notification/ManagedServicesTest.java
+++ b/services/tests/uiservicestests/src/com/android/server/notification/ManagedServicesTest.java
@@ -65,6 +65,7 @@
 
 import org.junit.Before;
 import org.junit.Test;
+import org.mockito.ArgumentCaptor;
 import org.mockito.Mock;
 import org.mockito.MockitoAnnotations;
 import org.mockito.invocation.InvocationOnMock;
@@ -1320,16 +1321,15 @@
                 APPROVAL_BY_COMPONENT);
         ComponentName cn = ComponentName.unflattenFromString("a/a");
 
-        service.registerSystemService(cn, 0);
-        when(context.bindServiceAsUser(any(), any(), anyInt(), any())).thenAnswer(invocation -> {
-            Object[] args = invocation.getArguments();
-            ServiceConnection sc = (ServiceConnection) args[1];
-            sc.onNullBinding(cn);
-            return true;
-        });
+        ArgumentCaptor<ServiceConnection> captor = ArgumentCaptor.forClass(ServiceConnection.class);
+        when(context.bindServiceAsUser(any(), captor.capture(), anyInt(), any()))
+                .thenAnswer(invocation -> {
+                    captor.getValue().onNullBinding(cn);
+                    return true;
+                });
 
         service.registerSystemService(cn, 0);
-        assertFalse(service.isBound(cn, 0));
+        verify(context).unbindService(captor.getValue());
     }
 
     @Test