enable heat in grenade

this enables heat in the grenade jobs. Because we need to explicitly
tell tempest what services to test, this doesn't actually test
heat (that will depend on additional grenade changes).

This is therefore a largely no-op change in normal runs which will
make it possible for the heat team to add real grenade support.

Change-Id: I6cfb2e4abf43abf91f96e85e82fcdd1fee3f9470
Merge "enable heat in grenade"