BuildKite pre-command: Improve log signal-to-noise ratio.

This removes noise from the package installation process (boring and
noisy), and adds logging for the shell commands that run after that
(which are more interesting).

PiperOrigin-RevId: 454273369

.buildkite/hooks/pre-command

@@ -7,7 +7,7 @@ buildkite-agent artifact download 'tools/bazeldefs/*' . || true
 function install_pkgs() {
   export DEBIAN_FRONTEND=noninteractive
   while true; do
-    if sudo -E apt-get update && sudo -E apt-get install -y "$@"; then
+    if sudo -E apt-get update -q && sudo -E apt-get install -qy "$@"; then
       break
     fi
   done
@@ -23,6 +23,8 @@ elif test -n "$(apt-cache search --names-only "^linux-gcp-headers-$(uname -r | c
   install_pkgs "linux-gcp-headers-$(uname -r | cut -d- -f1-2)"
 fi
 
+set -x
+
 # Setup for parallelization with PARTITION and TOTAL_PARTITIONS.
 export PARTITION=${BUILDKITE_PARALLEL_JOB:-0}
 PARTITION=$((${PARTITION}+1)) # 1-indexed, but PARALLEL_JOB is 0-indexed.