Revert "LayoutLib: Switch SimpleDateFormat to icu."

This reverts commit b556decf.

This is no longer needed as the SimpleDateFormat has been switched in
the framework. Also, the revert leaves the change to intellij inspection
profiles as is, because that change was independent of the main issue.

Change-Id: I6f4d7d9ddc10262b087ad6a2604fa50562fac043