Update (5/2/19 @ 4:15 PM ET): Kieron Quinn has shared even more screenshots (below) of the Google Play Store's update UI.
Google has rolled out (or has started testing) Material Theme redesign for apps like Google Photos, Google Calculator, Google Calendar, Google Home, Google Keep, Project Fi, Files, Google Drive and more. The latest app to join the Material Theme redesign party will be the Google Play Store, as first spotted by 9to5Google but also activated by us. The publication also spotted certain update-related strings within the app, which we at XDA-Developers believe is for installing APEX packages directly from the Play Store.
We activated the Google Material Theme redesign on the latest version of the Google Play Store, i.e. version 14.5.52, with help from XDA Recognized Developer Quinny899. With this redesign, the most significant change is the bottom bar that contains tabs for Home, Games, Movies & TV and Books sections for easier navigation. The icons are hollow and monochrome, changing to their assigned accent color when the tab is selected. The Search bar now has rounded corners. The homepage gets rid of the nested tabs and icons for categories. The homepage also sees the new rounded square icons being uniformly enforced.
The App Info page now features the Google Sans font. There is now a longer button for installing apps. The download indicator has also been modified, as it is now circular and around the app icon. In the "My Apps & Games" screen, there is a new Permissions section.
In addition to these Material Theme changes, 9to5Google spotted certain strings, which they have interpreted as pertaining to supporting initiating full Android system updates from Google Play.
<string name=”system_update_page_title”>System Update</string>
<string name=”system_update_page_download_button”>Download & Install</string>
<string name=”system_update_page_initializing_status”>Preparing…</string>
<string name=”system_update_page_installing_status”>Installing… Device will restart soon.</string>
<string name=”system_update_page_successful_status”>All good! Update complete.</string>
<string name=”system_update_page_error_status”>Sorry, something went wrong! Try again later.</string>
We believe, however, that these strings pertain to support for the new APEX packages that are already live in Android Q. There are currently six APEX packages within Android Q, and it will also be mandatory for OEMs to use Google's packages, according to our own source. Thus, the system update referred to in these strings are very likely for updating APEX modules, which are indeed system libraries, directly from the Play Store.
You can read more about APEX and how it is the biggest thing to happen to Android after Project Treble.
Via 1: 9to5GoogleVia 2: 9to5Google
Update: More screenshots
Kieron Quinn (Quinny898) has tweeted a few more screenshots of the new Google Play Store UI. This time we can see the reviews and music store section. He says this version is fairly stable with just the toolbar disappearing. It's possible we see the final version at Google I/O next week.