Add a logcat message for aborted background activity starts

Previously we just showed a toast and didn't log anything.
This needs to change as we start getting more and more bug reports
from early dogfooders, and more and more people will want to figure
out what's going on.

Bug: 110956953
Test: atest WmTests:ActivityStarterTests
Test: adb logcat | grep "Blocking background activity start"
Change-Id: I48483d33b28cbb18c633666b990c58144e54bde1

services/core/java/com/android/server/wm/ActivityStarter.java

@@ -749,7 +749,7 @@ class ActivityStarter {
         if (!abort) {
             abort |= shouldAbortBackgroundActivityStart(callingUid, callingPid, callingPackage,
                     realCallingUid, callerApp, originatingPendingIntent,
-                    allowBackgroundActivityStart);
+                    allowBackgroundActivityStart, intent);
         }
 
         // Merge the two options bundles, while realCallerOptions takes precedence.
@@ -898,7 +898,8 @@ class ActivityStarter {
 
     private boolean shouldAbortBackgroundActivityStart(int callingUid, int callingPid,
             final String callingPackage, int realCallingUid, WindowProcessController callerApp,
-            PendingIntentRecord originatingPendingIntent, boolean allowBackgroundActivityStart) {
+            PendingIntentRecord originatingPendingIntent, boolean allowBackgroundActivityStart,
+            Intent intent) {
         if (mService.isBackgroundActivityStartsEnabled()) {
             return false;
         }
@@ -911,19 +912,24 @@ class ActivityStarter {
             return false;
         }
         // don't abort if the callingUid is in the foreground or is a persistent system process
-        if (isUidForeground(callingUid) || isUidPersistentSystemProcess(callingUid)) {
+        final boolean isCallingUidForeground = isUidForeground(callingUid);
+        final boolean isCallingUidPersistentSystemProcess = isUidPersistentSystemProcess(
+                callingUid);
+        if (isCallingUidForeground || isCallingUidPersistentSystemProcess) {
             return false;
         }
         // take realCallingUid into consideration
+        final boolean isRealCallingUidForeground = isUidForeground(realCallingUid);
+        final boolean isRealCallingUidPersistentSystemProcess = isUidPersistentSystemProcess(
+                realCallingUid);
         if (realCallingUid != callingUid) {
             // don't abort if the realCallingUid is in the foreground and callingUid isn't
-            if (isUidForeground(realCallingUid)) {
+            if (isRealCallingUidForeground) {
                 return false;
             }
             // if the realCallingUid is a persistent system process, abort if the IntentSender
             // wasn't whitelisted to start an activity
-            if (isUidPersistentSystemProcess(realCallingUid) && (originatingPendingIntent != null)
-                    && allowBackgroundActivityStart) {
+            if (isRealCallingUidPersistentSystemProcess && allowBackgroundActivityStart) {
                 return false;
             }
         }
@@ -941,6 +947,18 @@ class ActivityStarter {
             return false;
         }
         // anything that has fallen through will currently be aborted
+        Slog.w(TAG, "Blocking background activity start [callingPackage: " + callingPackage
+                + "; callingUid: " + callingUid
+                + "; isCallingUidForeground: " + isCallingUidForeground
+                + "; isCallingUidPersistentSystemProcess: " + isCallingUidPersistentSystemProcess
+                + "; realCallingUid: " + realCallingUid
+                + "; isRealCallingUidForeground: " + isRealCallingUidForeground
+                + "; isRealCallingUidPersistentSystemProcess: "
+                        + isRealCallingUidPersistentSystemProcess
+                + "; originatingPendingIntent: " + originatingPendingIntent
+                + "; isBgStartWhitelisted: " + allowBackgroundActivityStart
+                + "; intent: " + intent
+                + "]");
         // TODO: remove this toast after feature development is done
         mService.mUiHandler.post(() -> {
             Toast.makeText(mService.mContext,