Bump kotlin_version from 1.3.61 to 1.4.31

Bumps `kotlin_version` from 1.3.61 to 1.4.31.

Updates `kotlin-gradle-plugin` from 1.3.61 to 1.4.31
- [Release notes](https://github.com/JetBrains/kotlin/releases)
- [Changelog](https://github.com/JetBrains/kotlin/blob/master/ChangeLog.md)
- [Commits](JetBrains/kotlin@v1.3.61...v1.4.31)

Updates `kotlin-stdlib-jdk7` from 1.3.61 to 1.4.31
- [Release notes](https://github.com/JetBrains/kotlin/releases)
- [Changelog](https://github.com/JetBrains/kotlin/blob/master/ChangeLog.md)
- [Commits](JetBrains/kotlin@v1.3.61...v1.4.31)

Signed-off-by: dependabot-preview[bot] <[email protected]>

build.gradle

@@ -8,7 +8,7 @@ buildscript {
     min_sdk_version = 14
     target_sdk_version = 28
 
-    kotlin_version = '1.3.61'
+    kotlin_version = '1.4.31'
     material_version = '1.2.1'
     appcompat_version = '1.2.0'
     core_version = '1.1.0'