Update to androidx, jdk8, including databinding errors using AS 3.4C8+

[RoarGronmo]

Please update to androidx, jdk8 and check if databinding is correct, importing to AS 3.4C8+ causes following errors:

• What went wrong:
  A problem occurred configuring project ':app'.

Could not resolve all files for configuration ':app:kapt'.
Could not find com.android.databinding:compiler:3.4.0-alpha08.
Searched in the following locations:
- https://dl.google.com/dl/android/maven2/com/android/databinding/compiler/3.4.0-alpha08/compiler-3.4.0-alpha08.pom
- https://dl.google.com/dl/android/maven2/com/android/databinding/compiler/3.4.0-alpha08/compiler-3.4.0-alpha08.jar
- https://jcenter.bintray.com/com/android/databinding/compiler/3.4.0-alpha08/compiler-3.4.0-alpha08.pom
- https://jcenter.bintray.com/com/android/databinding/compiler/3.4.0-alpha08/compiler-3.4.0-alpha08.jar
Required by:
project :app

RG