Convert lessons external link icon to icon button#260

MihaiCristianCondrea merged 2 commits intomainMihaiCristianCondrea/Android-Studio-Tutorials-Java-Edition:mainfrom

codex/add-icon-button-for-open-in-newMihaiCristianCondrea/Android-Studio-Tutorials-Java-Edition:codex/add-icon-button-for-open-in-newCopy head branch name to clipboard