Revert "Revert "Defer FGS notifications from legacy apps by default""

This reverts commit 33de1a2d4c.

Re-establishing this behavior now that the unit test failure has been
isolated and fixed.

Reason for revert: test/app fix
Bug: 175764941
Bug: 176849372
Test: atest TraceurUiTests:com.android.traceur.uitest.TraceurAppTests#testSuccessfulTracing
Test: ApiDemos

Change-Id: I3fa20e1a37eade5ee8de6f7e10d7eed851d877d1

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

@@ -1700,12 +1700,13 @@ public final class ActiveServices {
     // TODO: remove as part of fixing b/173627642
     @SuppressWarnings("AndroidFrameworkCompatChange")
     private void postFgsNotificationLocked(ServiceRecord r) {
+        final boolean isLegacyApp = (r.appInfo.targetSdkVersion < Build.VERSION_CODES.S);
         boolean showNow = !mAm.mConstants.mFlagFgsNotificationDeferralEnabled;
         if (!showNow) {
             // Legacy apps' FGS notifications are not deferred unless the relevant
             // DeviceConfig element has been set
             showNow = mAm.mConstants.mFlagFgsNotificationDeferralApiGated
-                    && r.appInfo.targetSdkVersion < Build.VERSION_CODES.S;
+                    && isLegacyApp;
         }
         if (!showNow) {
             // is the notification such that it should show right away?
@@ -1760,6 +1761,11 @@ public final class ActiveServices {
             Slog.d(TAG_SERVICE, "FGS " + r
                     + " notification in " + (when - now) + " ms");
         }
+        if (isLegacyApp) {
+            Slog.i(TAG_SERVICE, "Deferring FGS notification in legacy app "
+                    + r.appInfo.packageName + "/" + UserHandle.formatUid(r.appInfo.uid)
+                    + " : " + r.foregroundNoti);
+        }
         mAm.mHandler.postAtTime(mPostDeferredFGSNotifications, when);
     }
 

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

@@ -370,9 +370,9 @@ final class ActivityManagerConstants extends ContentObserver {
     volatile boolean mFlagFgsNotificationDeferralEnabled = true;
 
     // Restrict FGS notification deferral policy to only those apps that target
-    // API version S or higher.  Enabled by default; set to "false" to defer FGS
-    // notifications from legacy apps as well.
-    volatile boolean mFlagFgsNotificationDeferralApiGated = true;
+    // API version S or higher.  Disabled by default; set to "true" to force
+    // legacy app FGS notifications to display immediately in all cases.
+    volatile boolean mFlagFgsNotificationDeferralApiGated = false;
 
     // Time in milliseconds to defer FGS notifications after their transition to
     // the foreground state.
@@ -806,7 +806,7 @@ final class ActivityManagerConstants extends ContentObserver {
         mFlagFgsNotificationDeferralApiGated = DeviceConfig.getBoolean(
                 DeviceConfig.NAMESPACE_ACTIVITY_MANAGER,
                 KEY_DEFERRED_FGS_NOTIFICATIONS_API_GATED,
-                /*default value*/ true);
+                /*default value*/ false);
     }
 
     private void updateFgsNotificationDeferralInterval() {