Logs for test & debug blocks

This change adds logging for debuggable and test-only apps when they are
the caller and visibility of another app is blocked due to app
enumeration.

It also adds an adb command to turn logging on and off for other apps to
help developers while debugging issues.

Test: atest AppsFilterTest AppEnumerationTests PackageManagerPerfTest
Bug: 145623959
Change-Id: I1fa930ef40bf08b00c41f51aa25c50b2189395bf
diff --git a/services/core/java/com/android/server/pm/PackageManagerShellCommand.java b/services/core/java/com/android/server/pm/PackageManagerShellCommand.java
index 0f06c18..be17dd8 100644
--- a/services/core/java/com/android/server/pm/PackageManagerShellCommand.java
+++ b/services/core/java/com/android/server/pm/PackageManagerShellCommand.java
@@ -295,6 +295,8 @@
                     return runRollbackApp();
                 case "get-moduleinfo":
                     return runGetModuleInfo();
+                case "log-visibility":
+                    return runLogVisibility();
                 default: {
                     String nextArg = getNextArg();
                     if (nextArg == null) {
@@ -360,6 +362,36 @@
         return 1;
     }
 
+    private int runLogVisibility() {
+        final PrintWriter pw = getOutPrintWriter();
+        boolean enable = true;
+
+        String opt;
+        while ((opt = getNextOption()) != null) {
+            switch (opt) {
+                case "--disable":
+                    enable = false;
+                    break;
+                case "--enable":
+                    enable = true;
+                    break;
+                default:
+                    pw.println("Error: Unknown option: " + opt);
+                    return -1;
+            }
+        }
+
+        String packageName = getNextArg();
+        if (packageName != null) {
+            LocalServices.getService(PackageManagerInternal.class)
+                    .setVisibilityLogging(packageName, enable);
+        } else {
+            getErrPrintWriter().println("Error: no package specified");
+            return -1;
+        }
+        return 1;
+    }
+
     private int uninstallSystemUpdates() {
         final PrintWriter pw = getOutPrintWriter();
         List<String> failedUninstalls = new LinkedList<>();
@@ -3715,6 +3747,11 @@
         pw.println("      --all: show all module info");
         pw.println("      --installed: show only installed modules");
         pw.println("");
+        pw.println("  log-visibility [--enable|--disable] <PACKAGE>");
+        pw.println("    Turns on debug logging when visibility is blocked for the given package.");
+        pw.println("      --enable: turn on debug logging (default)");
+        pw.println("      --disable: turn off debug logging");
+        pw.println("");
         Intent.printIntentArgsHelp(pw , "");
     }