deps: revert protobuf to 3.19 and common-protos 2.8.3 (#798)

This reverts commit 51f59fc.

Author: suztomo

java-core/pom.xml

@@ -153,14 +153,14 @@
     <site.installationModule>google-cloud-core-parent</site.installationModule>
     <gax.version>2.13.0</gax.version>
     <google.api-common.version>2.1.5</google.api-common.version>
-    <google.common-protos.version>2.8.2</google.common-protos.version>
+    <google.common-protos.version>2.8.3</google.common-protos.version>
     <google.iam.version>1.3.0</google.iam.version>
     <google.auth.version>1.6.0</google.auth.version>
     <google.api.version>1.33.4</google.api.version>
     <google.http.version>1.41.7</google.http.version>
     <graalvm.version>22.0.0.2</graalvm.version>
     <grpc.version>1.45.1</grpc.version>
-    <protobuf.version>3.20.0</protobuf.version>
+    <protobuf.version>3.19.4</protobuf.version>
     <opencensus.version>0.31.0</opencensus.version>
     <annotations-api.version>1.3.2</annotations-api.version>
     <guava.version>31.1-jre</guava.version>