Make 'Next' button on Dropdown step enabled if navigated back after license attributes have been selected

>> Fixes: When attribution is selected, CC BY is set as the selected license in the state. When Going back to step one, then selecting that you already know which license you need, CC BY is automatically set as the selected license in the dropdown. This creates some weird behavior where there is a selected license in the dropdown, but the "Next Question" button is not enabled.

Signed-off-by: Olga Bulat <obulat@gmail.com>

Author: obulat

src/components/Stepper.vue

@@ -158,6 +158,11 @@ export default {
              */
             if (this.isLicenseAttribute(stepName)) {
                 this.$store.commit('setSelected', { stepName, isSelected })
+                // When the user first selects a license attribute, the dropdown step's Next button should be enabled
+                // as the dropdown will be populated with the selected license from the state
+                if (this.steps[5].selected === undefined && stepName === 'BY') {
+                    this.steps[5].selected = true
+                }
             }
             this.$set(this.steps, stepId, { ...this.steps[stepId], selected: isSelected })
             this.updateDisabledAndVisibleSteps(stepName, isSelected)