Revert^2 "aconfig: cache flag value in generated java code"

This reverts commit 257f64347df75b7fb64847be9469bfffc29fb63f.

Reason for revert: fix in Roboletric will subimt together with this change

Change-Id: I03c9ed627e6a4153db9c9074daf821ea6d19bc33
diff --git a/tools/aconfig/templates/Flags.java.template b/tools/aconfig/templates/Flags.java.template
index 66c4c5a..cf6604c 100644
--- a/tools/aconfig/templates/Flags.java.template
+++ b/tools/aconfig/templates/Flags.java.template
@@ -5,11 +5,11 @@
 
 /** @hide */
 public final class Flags \{
-{{- for item in class_elements}}
+{{- for item in flag_elements}}
     /** @hide */
     public static final String FLAG_{item.flag_name_constant_suffix} = "{item.device_config_flag}";
 {{- endfor }}
-{{ for item in class_elements}}
+{{ for item in flag_elements}}
 {{ -if not item.is_read_write }}
 {{ -if item.default_value }}
     @com.android.aconfig.annotations.AssumeTrueForR8