Do not use “-y” for package install

According to "code conventions" [1], do not use "-y" option.
Instead, use apt-get install package, yum install package,
or zypper install package.

[1] https://docs.openstack.org/doc-contrib-guide/writing-style/
code-conventions.html

Change-Id: I002607baadb90c8b0da4332a9eb7ca8e6f598f9f

doc/source/install/developer/all-in-one.rst

@@ -53,8 +53,8 @@ necessary
 
 ::
 
-      sudo apt-get update -y
-      sudo apt-get install -y --no-install-recommends -qq \
+      sudo apt-get update
+      sudo apt-get install --no-install-recommends -qq \
               curl \
               docker.io \
               nfs-common \

doc/source/install/multinode.rst

@@ -182,7 +182,7 @@ our hosts. Using our Ubuntu example:
 
 ::
 
-    sudo apt-get install ceph-common -y
+    sudo apt-get install ceph-common
 
 Kubernetes Node DNS Resolution
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~