Fix service_type in instance creation using heat services

parameters supplied to heat template should use service_type instead of hard-coded mysql

Fixes: Bug 1241655

Change-Id: I3cce6b35fc40f4ff4cc45b04714067956fb1869c
Fix white_box mode for integration tests.

* Removing outdated logic and old test paths that are
  hit when running instances tests in white_box mode.

Fixes: Bug #1243793
Change-Id: I944b63b9cf9ca0f5d8d2139cb2974f4c804ca30a
Merge "Fix white_box mode for integration tests."
Merge "Fix service_type in instance creation using heat services"