Provide API to access Intent that triggered StrictMode violation

Android 12 introduces a StrictMode check to warn developers if they
are launching an unsafe Intent (one that has been unparceled from the
delivered Intent). This commit provides an API to allow a developer
to access the Intent that triggered the StrictMode violation.

Bug: 178029824
Test: atest StrictModeTest
Test: Manually verified serialized violation does not result in
      an Exception
Change-Id: I392df3f80487503bc8235700ecb17c51d930830c

core/api/current.txt

@@ -31865,6 +31865,8 @@ package android.os.strictmode {
   }
 
   public final class UnsafeIntentLaunchViolation extends android.os.strictmode.Violation {
+    ctor public UnsafeIntentLaunchViolation(@NonNull android.content.Intent);
+    method @Nullable public android.content.Intent getIntent();
   }
 
   public final class UntaggedSocketViolation extends android.os.strictmode.Violation {

core/java/android/os/strictmode/UnsafeIntentLaunchViolation.java

@@ -17,10 +17,13 @@
 package android.os.strictmode;
 
 import android.annotation.NonNull;
+import android.annotation.Nullable;
 import android.app.PendingIntent;
 import android.content.Intent;
 import android.net.Uri;
 
+import java.util.Objects;
+
 /**
  * Violation raised when your app launches an {@link Intent} which originated
  * from outside your app.
@@ -46,8 +49,20 @@ import android.net.Uri;
  * not protected, your app is likely vulnerable to malicious apps.
  */
 public final class UnsafeIntentLaunchViolation extends Violation {
-    /** @hide */
+    private transient Intent mIntent;
+
     public UnsafeIntentLaunchViolation(@NonNull Intent intent) {
         super("Launch of unsafe intent: " + intent);
+        mIntent = Objects.requireNonNull(intent);
+    }
+
+    /**
+     * Return the {@link Intent} which caused this violation to be raised. Note
+     * that this value is not available if this violation has been serialized
+     * since intents cannot be serialized.
+     */
+    @SuppressWarnings("IntentBuilderName")
+    public @Nullable Intent getIntent() {
+        return mIntent;
     }
 }