Add stubs for new API triggerPostinstall

Test: th
Bug: 377557752
Change-Id: I73beaae7feebb12d944d59496db2cf8c89115e93
diff --git a/aosp/update_attempter_android.cc b/aosp/update_attempter_android.cc
index 9f7ec97..85f650c 100644
--- a/aosp/update_attempter_android.cc
+++ b/aosp/update_attempter_android.cc
@@ -1457,6 +1457,18 @@
   processor_->StartProcessing();
 }
 
+bool UpdateAttempterAndroid::TriggerPostinstall(const std::string& partition,
+                                                Error* error) {
+  if (error) {
+    return LogAndSetGenericError(
+        error,
+        __LINE__,
+        __FILE__,
+        __FUNCTION__ + std::string(" is not implemented"));
+  }
+  return false;
+}
+
 void UpdateAttempterAndroid::OnCleanupProgressUpdate(double progress) {
   for (auto&& callback : cleanup_previous_update_callbacks_) {
     callback->OnCleanupProgressUpdate(progress);