cypress: extend waitUntilCoreIsIdle retry window to 20s

Under heavy CI load, the default 10s retry window expires before
the unocommandresult of .uno:ReportWhenIdle arrives, causing
intermittent failures.

Change-Id: Icf9c1a6b2dc181e2a689c537f1f9085917465b16
Signed-off-by: Mohit Marathe <mohit.marathe@collabora.com>
Reviewed-on: https://gerrit.collaboraoffice.com/c/online/+/2067
Reviewed-by: Caolán McNamara <caolan.mcnamara@collabora.com>
Tested-by: Caolán McNamara <caolan.mcnamara@collabora.com>

Author: mohit-marathe

cypress_test/integration_tests/common/helper.js

@@ -1266,7 +1266,7 @@ function waitUntilCoreIsIdle(win) {
 		win.app.socket.sendMessage('uno .uno:ReportWhenIdle ' + JSON.stringify(idleArgs));
 	});
 
-	cy.wrap(null).should(function() {
+	cy.wrap(null, { timeout: Cypress.config('defaultCommandTimeout') * 2.0 }).should(function() {
 		var matchingCall = spy.getCalls().find(function(call) {
 			var evt = call.args && call.args[0];
 			var textMsg = evt && evt.textMsg;