deps: update dependency io.grpc:grpc-bom to v1.38.0 (#164)

Author: renovate-bot

pom.xml

@@ -65,7 +65,7 @@
     <site.installationModule>google-iam-parent</site.installationModule>
     <protobuf.version>3.17.0</protobuf.version>
     <junit.version>4.13.2</junit.version>
-    <grpc.version>1.37.0</grpc.version>
+    <grpc.version>1.38.0</grpc.version>
     <guava.version>30.1-android</guava.version>
   </properties>