manifest: android-8.1.0_r4 -> android-8.1.0_r11

Change-Id: If67a1ece11ce0c8b7ab2722cee20dc2fa8342418
diff --git a/default.xml b/default.xml
index e60c758..c6a9b1c 100644
--- a/default.xml
+++ b/default.xml
@@ -11,7 +11,7 @@
   <remote  name="aosp"
            fetch="https://android.googlesource.com"
            review="android-review.googlesource.com"
-           revision="refs/tags/android-8.1.0_r4" />
+           revision="refs/tags/android-8.1.0_r11" />
 
   <default revision="refs/heads/staging/lineage-15.1"
            remote="github"