Update Grails version & add Gradle 7.2 (#854)

grailsVersion=5.2.0 instead of grailsVersion=5.1.1

Add information about update Gradle version in Grails 5.

src/en/guide/upgrading/upgrading40x.adoc

@@ -6,7 +6,7 @@ You will need to upgrade your Grails version defined in `gradle.properties` as:
 .gradle.properties
 ----
 ...
-grailsVersion=5.1.1
+grailsVersion=5.2.0
 ...
 ----
 
@@ -38,6 +38,25 @@ gormVersion=7.2.0
 ...
 ----
 
+### Bump up gradle version
+
+Grails 5.2.x uses gradle 7.2
+
+[source, properties]
+.gradle-wrapper.properties
+----
+...
+distributionUrl=https\://services.gradle.org/distributions/gradle-7.2-bin.zip
+...
+----
+
+Also you can run this command
+
+[source, properties]
+----
+./gradlew wrapper --gradle-version 7.2
+----
+
 ### GORM for MonogDB Sync Driver
 
 The GORM for MongoDB is updated to support latest mongodb-driver-sync. If you are using GORM for MongoDB and doing something specific to MongoDB Driver or low level Mongo API then you might want to take a look at https://mongodb.github.io/mongo-java-driver/4.0/upgrading/[Upgrading to the 4.0 Driver]