Settings: don't try to allow NLSes with too-long component names

* NotificationAccessConfirmationActivity (triggered through CompanionDeviceManager) -> Don't show the dialog, bail out early similarly to other invalid inputs.
* NotificationAccessSettings (from Special App Access) -> No changes, but use the canonical constant now.
* ApprovalPreferenceController (used in NotificationAccessDetails) -> Disable the toggle, unless the NLS was previously approved (in which case it can still be removed).

Fixes: 260570119
Fixes: 286043036
Test: atest + manually
Change-Id: Ifc048311746c027e3683cdcf65f1079d04cf7c56
Merged-In: Ifc048311746c027e3683cdcf65f1079d04cf7c56

src/com/android/settings/applications/specialaccess/notificationaccess/ApprovalPreferenceController.java

@@ -81,6 +81,8 @@ public class ApprovalPreferenceController extends BasePreferenceController {
         final RestrictedSwitchPreference preference =
                 (RestrictedSwitchPreference) pref;
         final CharSequence label = mPkgInfo.applicationInfo.loadLabel(mPm);
+        final boolean isAllowedCn = mCn.flattenToShortString().length()
+                <= NotificationManager.MAX_SERVICE_COMPONENT_NAME_LENGTH;
         final boolean isEnabled = isServiceEnabled(mCn);
         preference.setChecked(isEnabled);
         preference.setOnPreferenceChangeListener((p, newValue) -> {
@@ -105,7 +107,8 @@ public class ApprovalPreferenceController extends BasePreferenceController {
                 return false;
             }
         });
-        preference.updateState(mCn.getPackageName(), mPkgInfo.applicationInfo.uid, isEnabled);
+        preference.updateState(
+                mCn.getPackageName(), mPkgInfo.applicationInfo.uid, isAllowedCn, isEnabled);
     }
 
     public void disable(final ComponentName cn) {

src/com/android/settings/notification/NotificationAccessConfirmationActivity.java

@@ -67,7 +67,9 @@ public class NotificationAccessConfirmationActivity extends Activity
         mUserId = getIntent().getIntExtra(EXTRA_USER_ID, UserHandle.USER_NULL);
         CharSequence mAppLabel;
 
-        if (mComponentName == null || mComponentName.getPackageName() == null) {
+        if (mComponentName == null || mComponentName.getPackageName() == null
+                || mComponentName.flattenToString().length()
+                > NotificationManager.MAX_SERVICE_COMPONENT_NAME_LENGTH) {
             finish();
             return;
         }

src/com/android/settings/notification/NotificationAccessSettings.java

@@ -66,7 +66,6 @@ public class NotificationAccessSettings extends EmptyTextSettings {
     private static final String TAG = "NotifAccessSettings";
     static final String ALLOWED_KEY = "allowed";
     static final String NOT_ALLOWED_KEY = "not_allowed";
-    private static final int MAX_CN_LENGTH = 500;
 
     private static final ManagedServiceSettings.Config CONFIG =
             new ManagedServiceSettings.Config.Builder()
@@ -150,7 +149,8 @@ public class NotificationAccessSettings extends EmptyTextSettings {
         for (ServiceInfo service : services) {
             final ComponentName cn = new ComponentName(service.packageName, service.name);
             boolean isAllowed = mNm.isNotificationListenerAccessGranted(cn);
-            if (!isAllowed && cn.flattenToString().length() > MAX_CN_LENGTH) {
+            if (!isAllowed && cn.flattenToString().length()
+                    > NotificationManager.MAX_SERVICE_COMPONENT_NAME_LENGTH) {
                 continue;
             }
 

tests/unit/src/com/android/settings/applications/specialaccess/notificationaccess/ApprovalPreferenceControllerTest.java

@@ -83,6 +83,36 @@ public class ApprovalPreferenceControllerTest {
 
     }
 
+    @Test
+    public void updateState_enabled() {
+        when(mAppOpsManager.noteOpNoThrow(anyInt(), anyInt(), anyString())).thenReturn(
+                AppOpsManager.MODE_ALLOWED);
+        when(mNm.isNotificationListenerAccessGranted(mCn)).thenReturn(true);
+        RestrictedSwitchPreference pref = new RestrictedSwitchPreference(
+                mContext);
+        pref.setAppOps(mAppOpsManager);
+
+        mController.updateState(pref);
+
+        assertThat(pref.isEnabled()).isTrue();
+    }
+
+    @Test
+    public void updateState_invalidCn_disabled() {
+        ComponentName longCn = new ComponentName("com.example.package",
+                com.google.common.base.Strings.repeat("Blah", 150));
+        mController.setCn(longCn);
+        when(mAppOpsManager.noteOpNoThrow(anyInt(), anyInt(), anyString())).thenReturn(
+                AppOpsManager.MODE_ALLOWED);
+        RestrictedSwitchPreference pref = new RestrictedSwitchPreference(
+                mContext);
+        pref.setAppOps(mAppOpsManager);
+
+        mController.updateState(pref);
+
+        assertThat(pref.isEnabled()).isFalse();
+    }
+
     @Test
     public void updateState_checked() {
         when(mAppOpsManager.noteOpNoThrow(anyInt(), anyInt(), anyString())).thenReturn(