Bump kotlin_version from 1.3.70 to 1.3.72

Bumps `kotlin_version` from 1.3.70 to 1.3.72.

Updates `kotlin-gradle-plugin` from 1.3.70 to 1.3.72
- [Release notes](https://github.com/JetBrains/kotlin/releases)
- [Changelog](https://github.com/JetBrains/kotlin/blob/master/ChangeLog.md)
- [Commits](https://github.com/JetBrains/kotlin/compare/v1.3.70...v1.3.72)

Updates `kotlin-stdlib` from 1.3.70 to 1.3.72
- [Release notes](https://github.com/JetBrains/kotlin/releases)
- [Changelog](https://github.com/JetBrains/kotlin/blob/master/ChangeLog.md)
- [Commits](https://github.com/JetBrains/kotlin/compare/v1.3.70...v1.3.72)

Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

build.gradle

@@ -1,6 +1,6 @@
 buildscript {
     ext {
-        kotlin_version = '1.3.70'
+        kotlin_version = '1.3.72'
         mockito_version = '3.2.4'
     }