RescueParty: Add a DeviceConfig killswitch

1. Add a killswitch DeviceConfig flag in case emergency rollback is
needed (e.g. PackageWatchdog doesn't behave correctly).
2. Register the namespace for native flag sync mapper so that we can
also use the flag to turn off native disaster recovery.

Test: Atest RescueParty & verified on local device
Bug: 149420506
Change-Id: I9a0b546c7229c8444947b522585dd2c5ed37a00b
(cherry picked from commit 1c0993cf12)

core/java/android/provider/DeviceConfig.java

@@ -399,6 +399,13 @@ public final class DeviceConfig {
     public static final String NAMESPACE_CONNECTIVITY_THERMAL_POWER_MANAGER =
             "connectivity_thermal_power_manager";
 
+    /**
+     * Namespace for configuration related features.
+     *
+     * @hide
+     */
+    public static final String NAMESPACE_CONFIGURATION = "configuration";
+
     private static final Object sLock = new Object();
     @GuardedBy("sLock")
     private static ArrayMap<OnPropertiesChangedListener, Pair<String, Executor>> sListeners =

services/core/java/com/android/server/RescueParty.java

@@ -99,6 +99,8 @@ public class RescueParty {
     private static final String PROP_DISABLE_RESCUE = "persist.sys.disable_rescue";
     private static final String PROP_VIRTUAL_DEVICE = "ro.hardware.virtual_device";
 
+    private static final String DEVICE_CONFIG_DISABLE_FLAG = "disable_rescue_party";
+
     private static final int PERSISTENT_MASK = ApplicationInfo.FLAG_PERSISTENT
             | ApplicationInfo.FLAG_SYSTEM;
 
@@ -114,6 +116,14 @@ public class RescueParty {
             return false;
         }
 
+        // We're disabled if the DeviceConfig disable flag is set to true.
+        // This is in case that an emergency rollback of the feature is needed.
+        if (DeviceConfig.getBoolean(
+                DeviceConfig.NAMESPACE_CONFIGURATION, DEVICE_CONFIG_DISABLE_FLAG, false)) {
+            Slog.v(TAG, "Disabled because of DeviceConfig flag");
+            return true;
+        }
+
         // We're disabled on all engineering devices
         if (Build.IS_ENG) {
             Slog.v(TAG, "Disabled because of eng build");

services/core/java/com/android/server/am/SettingsToPropertiesMapper.java

@@ -80,6 +80,7 @@ public class SettingsToPropertiesMapper {
     @VisibleForTesting
     static final String[] sDeviceConfigScopes = new String[] {
         DeviceConfig.NAMESPACE_ACTIVITY_MANAGER_NATIVE_BOOT,
+        DeviceConfig.NAMESPACE_CONFIGURATION,
         DeviceConfig.NAMESPACE_INPUT_NATIVE_BOOT,
         DeviceConfig.NAMESPACE_INTELLIGENCE_CONTENT_SUGGESTIONS,
         DeviceConfig.NAMESPACE_MEDIA_NATIVE,

services/tests/mockingservicestests/src/com/android/server/RescuePartyTest.java

@@ -79,6 +79,7 @@ public class RescuePartyTest {
     private static final String CALLING_PACKAGE2 = "com.package.name2";
     private static final String NAMESPACE1 = "namespace1";
     private static final String NAMESPACE2 = "namespace2";
+    private static final String DISABLE_RESCUE_PARTY_FLAG = "disable_rescue_party";
 
     private MockitoSession mSession;
     private HashMap<String, String> mSystemSettingsMap;
@@ -316,6 +317,13 @@ public class RescuePartyTest {
 
     @Test
     public void testExplicitlyEnablingAndDisablingRescue() {
+        // mock the DeviceConfig get call to avoid hitting
+        // android.permission.READ_DEVICE_CONFIG when calling real DeviceConfig.
+        doReturn(true)
+                .when(() -> DeviceConfig.getBoolean(
+                    eq(DeviceConfig.NAMESPACE_CONFIGURATION),
+                    eq(DISABLE_RESCUE_PARTY_FLAG),
+                    eq(false)));
         SystemProperties.set(RescueParty.PROP_ENABLE_RESCUE, Boolean.toString(false));
         SystemProperties.set(PROP_DISABLE_RESCUE, Boolean.toString(true));
         assertEquals(RescuePartyObserver.getInstance(mMockContext).execute(sFailingPackage,
@@ -326,6 +334,22 @@ public class RescuePartyTest {
                 PackageWatchdog.FAILURE_REASON_APP_NOT_RESPONDING));
     }
 
+    @Test
+    public void testDisablingRescueByDeviceConfigFlag() {
+        doReturn(true)
+                .when(() -> DeviceConfig.getBoolean(
+                    eq(DeviceConfig.NAMESPACE_CONFIGURATION),
+                    eq(DISABLE_RESCUE_PARTY_FLAG),
+                    eq(false)));
+        SystemProperties.set(RescueParty.PROP_ENABLE_RESCUE, Boolean.toString(false));
+
+        assertEquals(RescuePartyObserver.getInstance(mMockContext).execute(sFailingPackage,
+                PackageWatchdog.FAILURE_REASON_APP_NOT_RESPONDING), false);
+
+        // Restore the property value initalized in SetUp()
+        SystemProperties.set(RescueParty.PROP_ENABLE_RESCUE, Boolean.toString(true));
+    }
+
     @Test
     public void testHealthCheckLevels() {
         RescuePartyObserver observer = RescuePartyObserver.getInstance(mMockContext);