deps: update dependency com.google.protobuf:protobuf-bom to v3.10.0 (#27)

Author: renovate-bot

pom.xml

@@ -160,7 +160,7 @@
     <google.api.version>1.30.3</google.api.version>
     <google.http.version>1.32.0</google.http.version>
     <grpc.version>1.23.0</grpc.version>
-    <protobuf.version>3.9.1</protobuf.version>
+    <protobuf.version>3.10.0</protobuf.version>
     <opencensus.version>0.24.0</opencensus.version>
     <annotations-api.version>1.3.2</annotations-api.version>
     <guava.version>28.0-android</guava.version><!-- We are currently using the *-android version to support JDK7. -->