aconfig: add namespace field to flag_declaration and parsed_flag

Add a new field to the proto messages flag_declaration and parsed_flag.

The new field will be used verbatim as a parameter when calling
DeviceConfig.getBoolean to read the value of a READ_WRITE flag. See the
DeviceConfig API for more info.

Note: not to be confused with the old namespace field, which has been
renamed to package.

Bug: 285211724
Test: atest aconfig.test
Change-Id: I2181be7b5e98fc334e5277fb5f7e386f1fe0b550
diff --git a/tools/aconfig/templates/java.template b/tools/aconfig/templates/java.template
index 709af44..a3d3319 100644
--- a/tools/aconfig/templates/java.template
+++ b/tools/aconfig/templates/java.template
@@ -7,8 +7,8 @@
     public static boolean {item.method_name}() \{
         {{ if item.readwrite- }}
         return DeviceConfig.getBoolean(
-            "{package}",
-            "{item.feature_name}__{item.flag_name}",
+            "{item.device_config_namespace}",
+            "{item.device_config_flag}",
             {item.default_value}
         );
         {{ -else- }}