This commit improves logging during deploy start by:
1. Creating a common module to be sourced by shell scripts to
load general-use functions, thus reducing code duplication
between the scripts
2. Replacing plain "echo" commands on the scripts by logging
functions present on the common module
3. Adding timestamps to the log messages
4. Centralizing all scripts logs into software.log, favouring
the troubleshooting, now that log lines contain timestamps
and the process/script that generated them
This commit also deletes the ostree_mounts.yaml file since
it would be used by apt-ostree integration, which was dropped.
Test Plan
PASS: run deploy start successfully and verify that deploy start
log messages are logged with the expected format
Story: 2010676
Task: 49607
Change-Id: I0bdebde8147faa5b29a642e35bfaf26e9862ed0a
Signed-off-by: Heitor Matsui <heitorvieira.matsui@windriver.com>