yes. yes. respectively.

I hope the

(edited)

flag is here because you added that clarification afterwards 👌 better to avoid confusion

How can I get rid of the old jar in AS?

w: Runtime JAR files in the classpath should have the same version. These files were found in the classpath:
    /Users/xx/.gradle/caches/modules-2/files-2.1/org.jetbrains.kotlin/kotlin-stdlib-jdk7/1.2.20/583b3d6b6caef2b66042c8755d1ef8395d12d0b2/kotlin-stdlib-jdk7-1.2.20.jar (version 1.2)
    /Users/xx/.gradle/caches/modules-2/files-2.1/org.jetbrains.kotlin/kotlin-reflect/1.2.20/f6f78911d9abbc803697a9030962258d9bda49b3/kotlin-reflect-1.2.20.jar (version 1.2)
    **/Applications/Android Studio.app/Contents/gradle/m2repository/org/jetbrains/kotlin/kotlin-stdlib-jre7/1.1.51/kotlin-stdlib-jre7-1.1.51.jar (version 1.1)**
    /Users/xx/.gradle/caches/modules-2/files-2.1/org.jetbrains.kotlin/kotlin-stdlib/1.2.20/1ce9e25c74aade0aa039cce459f2906a8c8ffc8e/kotlin-stdlib-1.2.20.jar (version 1.2)

I have updated the Kotlin plugin to 1.2. I would expect the bundled jar to get updated too.