Drive instrumentation with build flag for C/C++

Bug: 328444881
Test: m
Change-Id: I20c92c61f855adb772d6aa173e85a6d8092460d7

aconfig/codegen/init.go

@@ -49,11 +49,12 @@ var (
 				` && ${aconfig} create-cpp-lib` +
 				`    --mode ${mode}` +
 				`    --cache ${in}` +
-				`    --out ${gendir}`,
+				`    --out ${gendir}` +
+				`    --allow-instrumentation ${debug}`,
 			CommandDeps: []string{
 				"$aconfig",
 			},
-		}, "gendir", "mode")
+		}, "gendir", "mode", "debug")
 
 	// For rust_aconfig_library: Generate Rust library
 	rustRule = pctx.AndroidStaticRule("rust_aconfig_library",