bump gradle to 5.2.1 (#23879)

Summary:
Bump Gradle to 5.2.1, includes many bug fixes and improvements, especially improved Kotlin DSL support.

[Android] [Changed] - bump Gradle to 5.2.1
Pull Request resolved: #23879

Reviewed By: hramos

Differential Revision: D14486430

Pulled By: cpojer

fbshipit-source-id: 3476516352ff2c947d65103cff6f37e27d888c2d

Author: dulmandakh

gradle/wrapper/gradle-wrapper.jar

@@ -1,5 +1,5 @@
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-5.0-all.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-5.2.1-all.zip
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists

gradle/wrapper/gradle-wrapper.properties

@@ -1,5 +1,5 @@
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-5.0-all.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-5.2.1-all.zip
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists