recovery: Do not abort install on detecting older security patch level

 * This allows going back to stock ROM to progress

Change-Id: If8a3ab7347e51c90337c4044826226ea11d6a327
diff --git a/install/install.cpp b/install/install.cpp
index 00cd331..c93f45c 100644
--- a/install/install.cpp
+++ b/install/install.cpp
@@ -379,7 +379,8 @@
   bool device_supports_virtual_ab = android::base::GetBoolProperty("ro.virtual_ab.enabled", false);
 
   const auto current_spl = android::base::GetProperty("ro.build.version.security_patch", "");
-  if (ViolatesSPLDowngrade(zip, current_spl)) {
+  if (ViolatesSPLDowngrade(zip, current_spl) &&
+      !(ui->IsTextVisible() && ask_to_continue_downgrade(ui->GetDevice()))) {
     LOG(ERROR) << "Denying OTA because it's SPL downgrade";
     return INSTALL_ERROR;
   }