Update gradle wrapper version to 6.7

Author: skydoves

gradle/wrapper/gradle-wrapper.properties

@@ -17,4 +17,4 @@ distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-6.6.1-all.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-6.7-all.zip