Update codegen to use single channel in sys prop

Update sys prop name from persist.device_config.<namespace>.<flag> to persist.aconfig_flags.aconfig_flags.<namespace>.<flag>

Bug: b/295379636
Change-Id: I78f00daa574dc016902dce4b9b4ec961f973693c
diff --git a/tools/aconfig/src/codegen_cpp.rs b/tools/aconfig/src/codegen_cpp.rs
index 530af49..30e564a 100644
--- a/tools/aconfig/src/codegen_cpp.rs
+++ b/tools/aconfig/src/codegen_cpp.rs
@@ -289,7 +289,7 @@
 
             virtual bool disabled_rw() override {
                 return server_configurable_flags::GetServerConfigurableFlag(
-                    "aconfig_test",
+                    "aconfig_flags.aconfig_test",
                     "com.android.aconfig.test.disabled_rw",
                     "false") == "true";
             }
@@ -300,7 +300,7 @@
 
             virtual bool enabled_rw() override {
                 return server_configurable_flags::GetServerConfigurableFlag(
-                    "aconfig_test",
+                    "aconfig_flags.aconfig_test",
                     "com.android.aconfig.test.enabled_rw",
                     "true") == "true";
             }
@@ -363,7 +363,7 @@
                       return it->second;
                 } else {
                   return server_configurable_flags::GetServerConfigurableFlag(
-                      "aconfig_test",
+                      "aconfig_flags.aconfig_test",
                       "com.android.aconfig.test.disabled_rw",
                       "false") == "true";
                 }
@@ -392,7 +392,7 @@
                       return it->second;
                 } else {
                   return server_configurable_flags::GetServerConfigurableFlag(
-                      "aconfig_test",
+                      "aconfig_flags.aconfig_test",
                       "com.android.aconfig.test.enabled_rw",
                       "true") == "true";
                 }