Add whether section is selected to amplitude event - #51318

@bethanyaconnor All of the current amplitude events are logging false for this parameter. I tested it on staging with a section selected...and the value was false in the network tab. I'm wondering if the page load event is firing before selectedSection has a value...? But the sectionParam const seems to be working to preserve the sectionId when a teacher clicks the "back to level" or "next level" links, and that const references the selectedSection prop...