Prevent the disabling of specified apps

Prevent the disabling of specified apps, avoiding cases
where disabling the app may result in an unusable system.

Bug: 200043113
Test: make RunSettingsRoboTests ROBOTEST_FILTER=ApplicationFeatureProviderImplTest

(cherry picked from https://android-review.googlesource.com/q/commit:e6279dd6a20ee254bab9a66e545b9dbaf1895db0)
Change-Id: I0b298af76cec20e4f31ec7411bbf3200a2869035

src/com/android/settings/applications/ApplicationFeatureProviderImpl.java

@@ -32,6 +32,7 @@ import android.content.pm.ServiceInfo;
 import android.content.pm.UserInfo;
 import android.location.LocationManager;
 import android.os.RemoteException;
+import android.os.SystemConfigManager;
 import android.os.UserManager;
 import android.service.euicc.EuiccService;
 import android.telecom.DefaultDialerManager;
@@ -58,6 +59,8 @@ public class ApplicationFeatureProviderImpl implements ApplicationFeatureProvide
     private final DevicePolicyManager mDpm;
     private final UserManager mUm;
     private final WebViewUpdateServiceWrapper mWebViewUpdateServiceWrapper;
+    private final SystemConfigManager mSystemConfigManager;
+
     /** Flags to use when querying PackageManager for Euicc component implementations. */
     private static final int EUICC_QUERY_FLAGS =
             PackageManager.MATCH_SYSTEM_ONLY | PackageManager.MATCH_DEBUG_TRIAGED_MISSING
@@ -75,6 +78,7 @@ public class ApplicationFeatureProviderImpl implements ApplicationFeatureProvide
         mDpm = dpm;
         mUm = UserManager.get(mContext);
         mWebViewUpdateServiceWrapper = wvusWrapper;
+        mSystemConfigManager = context.getSystemService(SystemConfigManager.class);
     }
 
     @Override
@@ -184,6 +188,7 @@ public class ApplicationFeatureProviderImpl implements ApplicationFeatureProvide
         if (locationHistoryPackage != null) {
             keepEnabledPackages.add(locationHistoryPackage);
         }
+        keepEnabledPackages.addAll(mSystemConfigManager.getPreventUserDisablePackages());
         return keepEnabledPackages;
     }
 

tests/robotests/src/com/android/settings/applications/ApplicationFeatureProviderImplTest.java

@@ -35,6 +35,7 @@ import android.content.pm.ResolveInfo;
 import android.content.pm.UserInfo;
 import android.location.LocationManager;
 import android.os.Build;
+import android.os.SystemConfigManager;
 import android.os.UserHandle;
 import android.os.UserManager;
 import android.platform.test.annotations.RequiresFlagsDisabled;
@@ -89,6 +90,9 @@ public final class ApplicationFeatureProviderImplTest {
 
     private final String PERMISSION = "some.permission";
 
+    private final List<String> PREVENT_USER_DISABLE_PACKAGES = List.of(
+            "prevent.disable.package1", "prevent.disable.package2", "prevent.disable.package3");
+
     @Mock
     private UserManager mUserManager;
     @Mock
@@ -103,6 +107,8 @@ public final class ApplicationFeatureProviderImplTest {
     private LocationManager mLocationManager;
     @Mock
     private WebViewUpdateServiceWrapper mWebViewUpdateServiceWrapper;
+    @Mock
+    private SystemConfigManager mSystemConfigManager;
 
     private ApplicationFeatureProvider mProvider;
 
@@ -116,6 +122,7 @@ public final class ApplicationFeatureProviderImplTest {
         when(mContext.getApplicationContext()).thenReturn(mContext);
         when(mContext.getSystemService(Context.USER_SERVICE)).thenReturn(mUserManager);
         when(mContext.getSystemService(Context.LOCATION_SERVICE)).thenReturn(mLocationManager);
+        when(mContext.getSystemService(SystemConfigManager.class)).thenReturn(mSystemConfigManager);
 
         mProvider = new ApplicationFeatureProviderImpl(mContext, mPackageManager,
                 mPackageManagerService, mDevicePolicyManager, mWebViewUpdateServiceWrapper);
@@ -395,6 +402,16 @@ public final class ApplicationFeatureProviderImplTest {
         assertThat(allowlist).contains("com.android.packageinstaller");
     }
 
+    @Test
+    public void getKeepEnabledPackages_shouldContainPreventUserDisablePackages() {
+        when(mSystemConfigManager.getPreventUserDisablePackages())
+                .thenReturn(PREVENT_USER_DISABLE_PACKAGES);
+
+        final Set<String> keepEnabledPackages = mProvider.getKeepEnabledPackages();
+
+        assertThat(keepEnabledPackages).containsAtLeastElementsIn(PREVENT_USER_DISABLE_PACKAGES);
+    }
+
     private void setUpUsersAndInstalledApps() {
         when(mUserManager.getProfiles(UserHandle.myUserId())).thenReturn(Arrays.asList(
                 new UserInfo(MAIN_USER_ID, "main", UserInfo.FLAG_ADMIN),