Delegate Kotlin standard library classes
Adds getFrameAtTime() support to ShadowMediametaDataRetriever
Changed method signature of String-valued getConstructor() to allow easier access to the no-arg constructor.
Added test coverage to getConstructor() calls and fixed latent bug in the String version.
Merge pull request #1267 from yanex/kotlin-service

Delegate Kotlin standard library classes.
Merge pull request #1268 from jacobtabak/master

Adds getFrameAtTime() support to ShadowMediametaDataRetriever.
Merge pull request #1269 from kriegfrj/noarg-constructor

Easier access to no-arg getConstructor().