recovery: Always log the update attempt.

An OTA may be skipped due to low battery. But we should always log it to
understand why an update _fails_ to apply.

Bug: 27893175
Change-Id: I50a3fbbb3e51035e0ac5f1cca150e283852825c3
(cherry picked from commit 568700189528c69a6cdd7a246127ce01463e033d)
diff --git a/recovery.cpp b/recovery.cpp
index 20c6ca1..4a3c7ef 100644
--- a/recovery.cpp
+++ b/recovery.cpp
@@ -1365,6 +1365,10 @@
     int status = INSTALL_SUCCESS;
 
     if (update_package != NULL) {
+        // It's not entirely true that we will modify the flash. But we want
+        // to log the update attempt since update_package is non-NULL.
+        modified_flash = true;
+
         if (!is_battery_ok()) {
             ui->Print("battery capacity is not enough for installing package, needed is %d%%\n",
                       BATTERY_OK_PERCENTAGE);