Unable to test toast message using protractor - protractor

Question

DOM for the toast message that i want to test is,
I tried the below code
When I run this code, I see the below error though it is able to locate the toast message. Please help me resolve this issue.
add_Button_loc = element(by.xpath("//button[#type='submit'][contains(text(),'Add')]"));
browser.wait(EC.elementToBeClickable(add_Button_loc), 5000);
expect(add_Button_loc.isPresent()).toBe(true);
toastmsg = element(by.tagName("p-growl")).$('[value="aaa Batch saved successfully"]');
add_Button_loc.click();
expect(toastmsg.isPresent()).toBe(true);
[10:17:26] W/element - more than one element found for locator By(css selector, p-growl) - the first result will be used
Failures:
1) ManageBatch Test Add Batch
Message:
Expected false to be true.
Stack:
Error: Failed expectation
at UserContext. (C:\Users\sarav\AppData\Roaming\npm\node_modules\protractor\example\manageBatch.js:43:32)
at C:\Users\sarav\AppData\Roaming\npm\node_modules\protractor\node_modules\jasminewd2\index.js:112:25
at new ManagedPromise (C:\Users\sarav\AppData\Roaming\npm\node_modules\protractor\node_modules\selenium-webdriver\lib\promise.js:1077:7)
at ControlFlow.promise (C:\Users\sarav\AppData\Roaming\npm\node_modules\protractor\node_modules\selenium-webdriver\lib\promise.js:2505:12)
at schedulerExecute (C:\Users\sarav\AppData\Roaming\npm\node_modules\protractor\node_modules\jasminewd2\index.js:95:18)
at TaskQueue.execute_ (C:\Users\sarav\AppData\Roaming\npm\node_modules\protractor\node_modules\selenium-webdriver\lib\promise.js:3084:14)
at TaskQueue.executeNext_