Using java_style enum generation for proto

This makes it easier to track various method parameters and simplifies
debug logging

Change-Id: Ib7c3d52590d0c36b2c8460c889ee3bead3454569
diff --git a/build.gradle b/build.gradle
index 4629caa..982ae2e 100644
--- a/build.gradle
+++ b/build.gradle
@@ -85,6 +85,7 @@
                     remove java
                     javanano {
                         option "java_package=launcher_log.proto|com.android.launcher3.userevent.nano"
+                        option "enum_style=java"
                     }
                 }
             }