Show a notification when a BG-launch FGS is restricted.

Previously each BG-launch FGS that is restricted has a logcat message, now we
also display a notification that has:
Title: "Foreground Service BG-Launch Restricted"
Content: "App restricted:" + app package name
Detail: intent of the FGS.

Use following command to turn on the FGS BG-launch restriction feature:
 adb shell device_config put activity_manager default_fgs_starts_restriction_enabled true
 adb shell device_config get activity_manager default_fgs_starts_restriction_enabled

Bug: 157473819
Test: Observe the notification when FGS BG-launch is restricted.
atest cts/tests/app/src/android/app/cts/ActivityManagerFgsBgStartTest.java#testFgsStartFromBG

Change-Id: Ia1ce1c7e103fbfa0a8487b0a3009b2d2ca61ba74

2 files changed, 36 insertions, 1 deletions

diff --git a/proto/src/system_messages.proto b/proto/src/system_messages.proto
index 34d2b73ac2db..15bd4dc66ccc 100644
--- a/proto/src/system_messages.proto
+++ b/proto/src/system_messages.proto
@@ -252,6 +252,10 @@ message SystemMessage {
     // Package: android
     NOTE_ID_WIFI_SIM_REQUIRED = 60;
 
+    // TODO: remove this notification after feature development is done
+    // Inform the user a foreground service is restricted from BG-launch.
+    NOTE_FOREGROUND_SERVICE_BG_LAUNCH = 61;
+
     // Display the Android Debug Protocol status
     // Package: android
     NOTE_ADB_WIFI_ACTIVE = 62;
diff --git a/services/core/java/com/android/server/am/ActiveServices.java b/services/core/java/com/android/server/am/ActiveServices.java
index 91a3fb003df2..b2e021fb74d1 100644
--- a/services/core/java/com/android/server/am/ActiveServices.java
+++ b/services/core/java/com/android/server/am/ActiveServices.java
@@ -25,6 +25,7 @@ import static android.os.Process.SHELL_UID;
 import static android.os.Process.SYSTEM_UID;
 import static android.os.Process.ZYGOTE_POLICY_FLAG_EMPTY;
 
+import static com.android.internal.messages.nano.SystemMessageProto.SystemMessage.NOTE_FOREGROUND_SERVICE_BG_LAUNCH;
 import static com.android.server.am.ActivityManagerDebugConfig.DEBUG_BACKGROUND_CHECK;
 import static com.android.server.am.ActivityManagerDebugConfig.DEBUG_FOREGROUND_SERVICE;
 import static com.android.server.am.ActivityManagerDebugConfig.DEBUG_MU;
@@ -119,6 +120,7 @@ import java.io.PrintWriter;
 import java.io.StringWriter;
 import java.lang.annotation.Retention;
 import java.lang.annotation.RetentionPolicy;
+import java.text.SimpleDateFormat;
 import java.util.ArrayList;
 import java.util.Comparator;
 import java.util.List;
@@ -228,6 +230,10 @@ public final class ActiveServices {
     // white listed packageName.
     ArraySet<String> mWhiteListAllowWhileInUsePermissionInFgs = new ArraySet<>();
 
+    // TODO: remove this after feature development is done
+    private static final SimpleDateFormat DATE_FORMATTER =
+            new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
+
     final Runnable mLastAnrDumpClearer = new Runnable() {
         @Override public void run() {
             synchronized (mAm) {
@@ -553,8 +559,9 @@ public final class ActiveServices {
                 if (r.mAllowStartForeground == FGS_FEATURE_DENIED
                         && mAm.mConstants.mFlagFgsStartRestrictionEnabled) {
                     Slog.w(TAG, "startForegroundService() not allowed due to "
-                                    + " mAllowStartForeground false: service "
+                                    + "mAllowStartForeground false: service "
                                     + r.shortInstanceName);
+                    showFgsBgRestrictedNotificationLocked(r);
                     forcedStandby = true;
                 }
             }
@@ -1459,6 +1466,7 @@ public final class ActiveServices {
                                     "Service.startForeground() not allowed due to "
                                             + "mAllowStartForeground false: service "
                                             + r.shortInstanceName);
+                            showFgsBgRestrictedNotificationLocked(r);
                             updateServiceForegroundLocked(r.app, true);
                             ignoreForeground = true;
                         }
@@ -5056,4 +5064,27 @@ public final class ActiveServices {
                 && code != FGS_FEATURE_ALLOWED_BY_UID_VISIBLE;
     }
 
+    // TODO: remove this notification after feature development is done
+    private void showFgsBgRestrictedNotificationLocked(ServiceRecord r) {
+        final Context context = mAm.mContext;
+        final String title = "Foreground Service BG-Launch Restricted";
+        final String content = "App restricted: " + r.mRecentCallingPackage;
+        final long now = System.currentTimeMillis();
+        final String bigText = DATE_FORMATTER.format(now) + " " + r.mInfoAllowStartForeground;
+        final String groupKey = "com.android.fgs-bg-restricted";
+        final Notification.Builder n =
+                new Notification.Builder(context,
+                        SystemNotificationChannels.ALERTS)
+                        .setGroup(groupKey)
+                        .setSmallIcon(R.drawable.stat_sys_vitals)
+                        .setWhen(0)
+                        .setColor(context.getColor(
+                                com.android.internal.R.color.system_notification_accent_color))
+                        .setTicker(title)
+                        .setContentTitle(title)
+                        .setContentText(content)
+                        .setStyle(new Notification.BigTextStyle().bigText(bigText));
+        context.getSystemService(NotificationManager.class).notifyAsUser(Long.toString(now),
+                NOTE_FOREGROUND_SERVICE_BG_LAUNCH, n.build(), UserHandle.ALL);
+    }
 }