deps: update gRPC to 1.38.0 (#2088)

@suztomo

Author: elharo

boms/cloud-oss-bom/pom.xml

@@ -47,7 +47,7 @@
     <guava.version>30.1.1-android</guava.version>
     <google.cloud.java.version>0.154.0</google.cloud.java.version>
     <google.cloud.core.version>1.94.8</google.cloud.core.version>
-    <io.grpc.version>1.37.1</io.grpc.version>
+    <io.grpc.version>1.38.0</io.grpc.version>
     <http.version>1.39.2</http.version>
     <protobuf.version>3.17.0</protobuf.version>
     <!-- We don't use gax-bom because it includes the artifacts with 'testlib' classifier.