Install procps (#1932)

The schema verifier script needs pgrep and pkill, which do not come with
Debian.

release/schema-deployer/Dockerfile

@@ -31,7 +31,7 @@ RUN apt-get update -y \
     && locale-gen en_US.UTF-8 \
     && apt-get install apt-utils -y \
     && apt-get upgrade -y \
-    && apt-get install openjdk-11-jdk-headless -y
+    && apt-get install openjdk-11-jdk-headless curl -y
 
 # Get netstat, used for checking Cloud SQL proxy readiness.
 RUN apt-get install net-tools

release/schema-verifier/Dockerfile

@@ -36,7 +36,7 @@ RUN apt-get update -y \
            'echo "deb http://apt.postgresql.org/pub/repos/apt $(lsb_release -cs)-pgdg main" \
            > /etc/apt/sources.list.d/pgdg.list' \
     && apt-get update -y \
-    && apt install postgresql-client-11 -y
+    && apt install postgresql-client-11 procps -y
 
 # Use unzip to extract files from jars.
 RUN apt-get install zip -y