Bump kotlin_version from 1.4.30 to 1.5.0

Bumps `kotlin_version` from 1.4.30 to 1.5.0.

Updates `kotlin-gradle-plugin` from 1.4.30 to 1.5.0
- [Release notes](https://github.com/JetBrains/kotlin/releases)
- [Changelog](https://github.com/JetBrains/kotlin/blob/master/ChangeLog.md)
- [Commits](https://github.com/JetBrains/kotlin/commits)

Updates `kotlin-stdlib-jdk7` from 1.4.30 to 1.5.0
- [Release notes](https://github.com/JetBrains/kotlin/releases)
- [Changelog](https://github.com/JetBrains/kotlin/blob/master/ChangeLog.md)
- [Commits](https://github.com/JetBrains/kotlin/commits)

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

build.gradle

@@ -2,7 +2,7 @@
 
 buildscript {
     ext{
-        kotlin_version = '1.4.30'
+        kotlin_version = '1.5.0'
         coroutine_version = "1.0.1"
         retrofit = "2.5.0"
         lifecycle_version = "1.1.1"