Bump WAIT_FOR_LOADER_BUFFER_MS to 3000 ms (#867)

Bump the value passed to the cypress env variable from 500 to 3000 ms
when executing `yarn cypress:run-with-security`

Issue:
opensearch-project/OpenSearch-Dashboards#5039

Signed-off-by: Kawika Avilla <kavilla414@gmail.com>
(cherry picked from commit 503ebf7)

package.json

@@ -7,8 +7,8 @@
     "test": "echo \"Error: no test specified\" && exit 1",
     "cypress:open": "cypress open",
     "cypress:run-without-security": "env TZ=America/Los_Angeles NO_COLOR=1 cypress run --headless --env SECURITY_ENABLED=false",
-    "cypress:run-with-security": "env TZ=America/Los_Angeles NO_COLOR=1 cypress run --headless --env SECURITY_ENABLED=true,openSearchUrl=https://localhost:9200,WAIT_FOR_LOADER_BUFFER_MS=500",
-    "cypress:run-with-security-and-aggregation-view": "env TZ=America/Los_Angeles NO_COLOR=1 cypress run --headless --env SECURITY_ENABLED=true,openSearchUrl=https://localhost:9200,AGGREGATION_VIEW=true,WAIT_FOR_LOADER_BUFFER_MS=500",
+    "cypress:run-with-security": "env TZ=America/Los_Angeles NO_COLOR=1 cypress run --headless --env SECURITY_ENABLED=true,openSearchUrl=https://localhost:9200,WAIT_FOR_LOADER_BUFFER_MS=3000",
+    "cypress:run-with-security-and-aggregation-view": "env TZ=America/Los_Angeles NO_COLOR=1 cypress run --headless --env SECURITY_ENABLED=true,openSearchUrl=https://localhost:9200,AGGREGATION_VIEW=true,WAIT_FOR_LOADER_BUFFER_MS=3000",
     "cypress:run-plugin-tests-without-security": "yarn cypress:run-without-security --spec 'cypress/integration/plugins/*/*.js'",
     "cypress:run-plugin-tests-with-security": "yarn cypress:run-with-security --spec 'cypress/integration/plugins/*/*.js'",
     "cypress:release-chrome": "yarn cypress:run-with-security --browser chrome --spec 'cypress/integration/core-opensearch-dashboards/opensearch-dashboards/*.js,cypress/integration/plugins/*/*'",