build: bump Kotlin to 1.2.40
build: bump Kotlin to 1.2.40

jeeb/mpv-android,jeeb/mpv-android,mpv-android/mpv-android,jeeb/mpv-android,mpv-android/mpv-android,mpv-android/mpv-android,mpv-android/mpv-android,jeeb/mpv-android,jeeb/mpv-android,mpv-android/mpv-android