Add some allegedly missing kotlin minification rules

[d4vidi]

Description

• This pull request addresses the issue described here: java.lang.NoClassDefFoundError: Failed resolution of: Lkotlin/jvm/internal/FunctionReference; #2837

In this pull request, I have (blindly^*) added pro-guard rules which will force-keep some Kotlin stdlib classes, corresponding to reports of missing class - as in #2837 and #1994.

^* Unfortunately, I haven't managed to to have similar crash issues reproduced on our example project. Nevertheless, I've analyzed the APK's alongside R8's output files (seeds.txt, in particular), and have managed to prove that indeed with the new rules in place, the missing kotlin classes do get bundled into the test apk.