Our build is fine when building with gradle plugin version 3.5.3 but we get the error below with plugin 3.6.0 and 3.6.1:

=== LOG ==============
$ ./gradlew clean build
...
... <<snip>>
...
> Task :app:minifyReleaseWithR8
R8: Library class android.test.AndroidTestCase extends program class junit.framework.TestCase
R8: Library class android.test.AndroidTestRunner extends program class junit.runner.BaseTestRunner
R8: Library class android.test.InstrumentationTestCase extends program class junit.framework.TestCase
R8: Library class android.test.InstrumentationTestSuite extends program class junit.framework.TestSuite
/Users/awardak/.gradle/caches/transforms-2/files-2.1/fef1474bbb7e9b673f1d467589f0ef14/jetified-cnc-android-sdk-3.15.9-runtime.jar: R8: NullPointerException during IR Conversion

> Task :app:minifyReleaseWithR8 FAILED
====================

I've tried the builds mentioned in the following comments of another ticket and they all give the above error as well:
- https://issuetracker.google.com/issues/150330356#comment16
- https://issuetracker.google.com/issues/150330356#comment26