Twitter left the code in for favorites/stars when the moved to hearts. You can still see them if you have Chrome/Opera/Safari (or any browser with a JavaScript console).
Use the keyboard shortcut Command + Option + J (Mac) or Control + Shift + J (Windows/Linux) to open the Chrome Dev Console. This might be different on other browsers.
Click the Console tab, paste this in, and press enter:
$( ".js-actionFavorite" ).each(function( index ) {$(this).html('<button class="ProfileTweet-actionButton js-actionButton js-actionFavorite" type="button"><div class="IconContainer js-tooltip" data-original-title="Like"><span class="Icon Icon--favorite"></span><span class="u-hiddenVisually">Favorite</span></div><div class="IconTextContainer"><span class="ProfileTweet-actionCount"><span class="ProfileTweet-actionCountForPresentation" aria-hidden="true">1</span></span></div></button>');});