Enable turbine for api generating annotation processors when using kotlin

Normally turbine is disabled when an api generating annotation processor
is in use because the annotation processors are run in javac, so any
generated api would not be present in the turbine header jar.  When
compiling with kotlin and annotation processors, the annotation processors
(including any that generate api) are run in an extra turbine invocation
to generate sources to make the results visible to kotlinc, and so can
also be compiled by the normal turbine invocation.  Force turbine enabled
when kotlin sources are present.

Test: m SystemUI
Bug: 222095735
Change-Id: I5fcfe67e46cb4a4e90388f088327488959b6571f