Let self-targeting apps be able access OverlayManager

Self-targeting apps can't get an OverlayManager instance without the
system privilege.  This patch makes sure that the self-targeting
application can get an OverlayManager instance via Context.

```
OverlayManager overlayManager =
         context.getSystemService(OverlayManager.class);
```

In order to make the self-targeting feature compatible in the future,
this patch adds SELF_TARGETING_OVERLAY compatibility feature.

Test: atest \
          OverlayHostTests \
          OverlayDeviceTests \
          SelfTargetingOverlayDeviceTests \
          OverlayRemountedTest \
          FrameworksServicesTests:com.android.server.om \
          CtsContentTestCases:android.content.om.cts \
          idmap2_tests

Bug: 205919743
Change-Id: Ib0b619a2a54e22d31e6c14bf700e421688b6f506

2 files changed, 20 insertions, 1 deletions

diff --git a/core/java/android/app/SystemServiceRegistry.java b/core/java/android/app/SystemServiceRegistry.java
index e54a0841dd26..5d87012ec7e7 100644
--- a/core/java/android/app/SystemServiceRegistry.java
+++ b/core/java/android/app/SystemServiceRegistry.java
@@ -58,6 +58,7 @@ import android.companion.CompanionDeviceManager;
 import android.companion.ICompanionDeviceManager;
 import android.companion.virtual.IVirtualDeviceManager;
 import android.companion.virtual.VirtualDeviceManager;
+import android.compat.Compatibility;
 import android.content.ClipboardManager;
 import android.content.ContentCaptureOptions;
 import android.content.Context;
@@ -1092,7 +1093,10 @@ public final class SystemServiceRegistry {
                 new CachedServiceFetcher<OverlayManager>() {
             @Override
             public OverlayManager createService(ContextImpl ctx) throws ServiceNotFoundException {
-                IBinder b = ServiceManager.getServiceOrThrow(Context.OVERLAY_SERVICE);
+                final IBinder b =
+                        (Compatibility.isChangeEnabled(OverlayManager.SELF_TARGETING_OVERLAY))
+                                ? ServiceManager.getService(Context.OVERLAY_SERVICE)
+                                : ServiceManager.getServiceOrThrow(Context.OVERLAY_SERVICE);
                 return new OverlayManager(ctx, IOverlayManager.Stub.asInterface(b));
             }});
 
diff --git a/core/java/android/content/om/OverlayManager.java b/core/java/android/content/om/OverlayManager.java
index 94275aea0c4d..812f6b0fc34b 100644
--- a/core/java/android/content/om/OverlayManager.java
+++ b/core/java/android/content/om/OverlayManager.java
@@ -92,6 +92,21 @@ public class OverlayManager {
     private static final long THROW_SECURITY_EXCEPTIONS = 147340954;
 
     /**
+     * Applications can use OverlayManager to create overlays to overlay on itself resources. The
+     * overlay target is itself and the work range is only in caller application.
+     *
+     * <p>In {@link android.content.Context#getSystemService(String)}, it crashes because of {@link
+     * java.lang.NullPointerException} if the parameter is OverlayManager. if the self-targeting is
+     * enabled, the caller application can get the OverlayManager instance to use self-targeting
+     * functionality.
+     *
+     * @hide
+     */
+    @ChangeId
+    @EnabledSince(targetSdkVersion = Build.VERSION_CODES.UPSIDE_DOWN_CAKE)
+    public static final long SELF_TARGETING_OVERLAY = 205919743;
+
+    /**
      * Creates a new instance.
      *
      * @param context The current context in which to operate.