Updating google-cloud-nio to 0.81.0 (#5752)

* updating google-cloud-nio 0.80.0-alpha -> 0.81.0-alpha
* this finally fixes #5447 by moving the stacktrace to debug verbosity

build.gradle

@@ -70,7 +70,7 @@ final testNGVersion = '6.11'
 // Using the shaded version to avoid conflicts between its protobuf dependency
 // and that of Hadoop/Spark (either the one we reference explicitly, or the one
 // provided by dataproc).
-final googleCloudNioDependency = 'com.google.cloud:google-cloud-nio:0.80.0-alpha:shaded'
+final googleCloudNioDependency = 'com.google.cloud:google-cloud-nio:0.81.0-alpha:shaded'
 
 final baseJarName = 'gatk'
 final secondaryBaseJarName = 'hellbender'