Support generating coverage report for Kotlin tests

Currently, only *.java are consider as source files,
and It's accidentally blocking the capability of
generating code coverage for Kotlin language.
Adding support for Kotlin (*.kt) files along with
Java files.

Test: make RunXXX-jacoco

Change-Id: I6c5b48e2cfd256be4cc916ec46955603171e10f3
1 file changed