Add "force-read-only" mode to xx_aconfig_library build rules

Test: added unit tests and CI
Bug: 317115655
Change-Id: Ia72159ffe072f9b4997f0d4d55a7b3db5356f5ed
diff --git a/aconfig/codegen/cc_aconfig_library_test.go b/aconfig/codegen/cc_aconfig_library_test.go
index 3de4626..c5ff6a1 100644
--- a/aconfig/codegen/cc_aconfig_library_test.go
+++ b/aconfig/codegen/cc_aconfig_library_test.go
@@ -29,6 +29,7 @@
 	{"mode: `production`,", "production"},
 	{"mode: `test`,", "test"},
 	{"mode: `exported`,", "exported"},
+	{"mode: `force-read-only`,", "force-read-only"},
 }
 
 func TestCCCodegenMode(t *testing.T) {