fix(plan-patches/bosh-lite-*): Add medium VM type to Cloud Config

Adds a medium VM type to the Cloud Configs of the bosh-lite-gcp and
bosh-lite-aws plan patches. This is a trivial change because VM types
don't matter in BOSH Lite. However, CF-D now requires a medium VM type,
so this change will smooth deployment.

Author: ctlong

plan-patches/bosh-lite-aws/cloud-config/cloud-confg.yml

@@ -70,3 +70,4 @@
   - name: minimal
   - name: small
   - name: small-highmem
+  - name: medium

plan-patches/bosh-lite-gcp/cloud-config/bosh-lite.yml

@@ -70,3 +70,4 @@
   - name: minimal
   - name: small
   - name: small-highmem
+  - name: medium