deps: update dependency com.google.auth:google-auth-library-bom to v0.19.0 (#23)

Author: renovate-bot

pom.xml

@@ -66,7 +66,7 @@
  <google.core.version>1.91.1</google.core.version>
  <google.api-common.version>1.8.1</google.api-common.version>
  <google.common-protos.version>1.17.0</google.common-protos.version>
- <google.auth.version>0.18.0</google.auth.version>
+ <google.auth.version>0.19.0</google.auth.version>
  <gax.version>1.50.1</gax.version>
  <grpc.version>1.26.0</grpc.version>
  <protobuf.version>3.11.1</protobuf.version>