Update installer BUILD doc with correct information (#1121)

installer/BUILD.md

@@ -36,18 +36,21 @@ sudo ./build/build.sh ova-dev
 ```
 
 If called with the values below, `build.sh` will include the Harbor version from
-`installer/build/harbor.tgz`, the VIC Engine version from `installer/build/vic.tar.gz`, and 
+`installer/build/harbor.tgz`, the VIC Engine version from `installer/build/vic_XXXX.tar.gz`, and 
 Admiral tag `vic_dev` (since `--admiral` was not specified it defaults to the `vic_dev` tag)
 ```
-./build/build.sh ova-dev --harbor harbor.tgz --vicengine vic.tar.gz
+./build/build.sh ova-dev --harbor harbor.tgz --vicengine vic_XXXX.tar.gz
 ```
 
 If called with the values below, `build.sh` will include the Harbor and VIC Engine versions
 specified by their respective URLs, and Admiral tag `vic_v1.1.1`
 ```
-./build/build.sh ova-dev --admiral v1.1.1 --harbor https://example.com/harbor.tgz --vicengine https://example.com/vic.tar.gz
+./build/build.sh ova-dev --admiral v1.1.1 --harbor https://example.com/harbor.tgz --vicengine https://example.com/vic_XXXX.tar.gz
 ```
 
+Note: the VIC Engine artifact used when building the OVA must be named following the `vic_*.tar.gz` format.
+This is required by the OVA in order to automatically configure the VIC Engine UI plugins correctly for installation.
+
 #### Upload
 
 You can upload the ova builds to the `vic-product-ova-builds` and `vic-product-ova-releases` in google cloud.