Store/parse date in BuildUtils using consistent timezone (ie, UTC)

Series of events:

• Someone cuts a release of Bamboo in Australia, the time in BuildUtils.java is an Australian time, eg 14:00 AEST, or 04:00 UTC, or 21:00 the day before PST.
• Studio consumes that release immediately, and commits the update
• Studios Bamboo server attempts to build and run studio func tests
• The date is parsed in BuildUtils.java, and is read in as 14:00PST, because the timezone of the build server is PST. Current time is 22:00PST the day before, so the build date is 18 hours in the future.
• Studio has a 3 hour time bomb license, so the maintenance expiry date is 3 hours from now (22:00 PST), which is 01:00 PST, 13 hours before the date parsed from BuildUtils.java
• Bamboo refuses to start saying the build is too new for the maintenance period. Studio team has to wait 13 hours before their build starts working again.

Storing and parsing the date using the same time zone would fix this issue.