deps: update dependency com.google.api:gax-bom to v1.50.1 (#73)

Author: renovate-bot

pom.xml

@@ -152,7 +152,7 @@
     <github.global.server>github</github.global.server>
     <site.installationModule>google-cloud-core-parent</site.installationModule>
 
-    <gax.version>1.49.1</gax.version>
+    <gax.version>1.50.1</gax.version>
     <google.api-common.version>1.8.1</google.api-common.version>
     <google.common-protos.version>1.17.0</google.common-protos.version>
     <google.iam.version>0.13.0</google.iam.version>