Pass packages to install as a list

Instead of using the slower loop, pass the
list directly to the install task to do
them all at once.

Change-Id: I827dad684a259f15cdf24a59dfb26e05e1f7826d

tasks/glance_install.yml

@@ -15,7 +15,7 @@
 
 - name: Install distro packages
   package:
-    name: "{{ item }}"
+    name: "{{ glance_distro_packages }}"
     state: "{{ glance_package_state }}"
     update_cache: "{{ (ansible_pkg_mgr == 'apt') | ternary('yes', omit) }}"
     cache_valid_time: "{{ (ansible_pkg_mgr == 'apt') | ternary(cache_timeout, omit) }}"
@@ -23,7 +23,6 @@
   until: install_packages|success
   retries: 5
   delay: 2
-  with_items: "{{ glance_distro_packages }}"
 
 - name: Create developer mode constraint file
   copy: