feat(integration test) test omni node dev mod work with dev_json file (#7511)

Closes #7452 

Adds new test for omni node on dev mode working correctly with
dev_chain_spec.json

@skunert

---------

Co-authored-by: cmd[bot] <41898282+github-actions[bot]@users.noreply.github.com>

Author: MrishoLukamba

docs/sdk/src/guides/your_first_node.rs

@@ -305,4 +305,33 @@ mod tests {
 			test_runtime_preset(FIRST_RUNTIME, 1000, preset);
 		});
 	}
+
+	#[test]
+	fn omni_node_dev_mode_works() {
+		//Omni Node in dev mode works with parachain's template `dev_chain_spec`
+		let dev_chain_spec = std::env::current_dir()
+			.unwrap()
+			.parent()
+			.unwrap()
+			.parent()
+			.unwrap()
+			.join("templates")
+			.join("parachain")
+			.join("dev_chain_spec.json");
+
+		maybe_build_omni_node();
+		let omni_node = find_release_binary(OMNI_NODE).unwrap();
+
+		let output = Command::new(omni_node)
+			.arg("--dev")
+			.args(["--chain", dev_chain_spec.to_str().unwrap()])
+			.timeout(std::time::Duration::from_secs(70))
+			.output()
+			.unwrap();
+
+		// atleast  blocks should be imported
+		assert!(String::from_utf8(output.stderr)
+			.unwrap()
+			.contains(format!("Imported #{}", 7).to_string().as_str()));
+	}
 }