Update dependency androidx.preference:preference to v1.2.0

Author: renovate-bot

build.gradle

@@ -27,7 +27,7 @@ ext {
     espressoVersion = '2.2.2'
     retrofitVersionLatest = '2.1.0'
     okHttp3Version = '3.5.0'
-    preference = '1.1.0'
+    preference = '1.2.0'
     rxJavaVersion = '1.1.4'
     rxAndroidVersion = '1.1.0'