Auto capitalize enums name in Ruby (#10454)

This closes #1965.
diff --git a/ruby/tests/generated_code.proto b/ruby/tests/generated_code.proto
index bfdfa5a..5f017ba 100644
--- a/ruby/tests/generated_code.proto
+++ b/ruby/tests/generated_code.proto
@@ -67,6 +67,8 @@
   A = 1;
   B = 2;
   C = 3;
+
+  v0 = 4;
 }
 
 message testLowercaseNested {