Accessibility: Ensure button has discernible text

[ElinorW]

URL: https://developer.microsoft.com/en-us/graph/graph-explorer

Path:
div[data-focuszone-id="FocusZone81"] > .ms-Pivot-overflowMenuButton.overflowMenuButton-220.ms-Button--hasMenu

Snippet:

Fix ONE of the following:
Element does not have inner text that is visible to screen readers
aria-label attribute does not exist or is empty
aria-labelledby attribute does not exist, references elements that do not exist or references elements that are empty
Element has no title attribute
Element's default semantics were not overridden with role="none" or role="presentation"