Fix duplicate id issue with settings_block.vue

Description

Identified in !176100 (merged) with this LOC. It looks like settings_block.vue creates 2 elements with the same id which is not only invalid HTML, but also freaks Capyabara out :|

Let's fix this by adding a -content postfix to the collapseId, and also verify that the fix won't break any existing usage of settings_block.vue.