Update protobuf to version 3.21.4. (#5078)

build-scripts/protobuf-common.gradle

@@ -20,7 +20,7 @@ android {
 
 protobuf {
     protoc {
-        artifact = 'com.google.protobuf:protoc:3.21.2'
+        artifact = "com.google.protobuf:protoc:$protobuf_version"
     }
     generateProtoTasks {
         all().each { task ->

build.gradle

@@ -22,7 +22,7 @@ buildscript {
         robolectric_core_version = '4.8.1'
         rust_android_gradle_version = '0.9.3'
         espresso_core_version = '3.3.0'
-        protobuf_version = '3.21.2'
+        protobuf_version = '3.21.4'
         gradle_protobuf_version = '0.8.19'
     }