Bump version to 5.1.9

app/build.gradle

@@ -61,8 +61,8 @@ protobuf {
     }
 }
 
-def canonicalVersionCode = 768
-def canonicalVersionName = "5.1.8"
+def canonicalVersionCode = 769
+def canonicalVersionName = "5.1.9"
 
 def postFixSize = 10
 def abiPostFix = ['universal'   : 0,