Cwa-website: FAQ: Google ENS incompatible with Android 5.0 (API 21) given as outdated reason for non-support in CWA

[MikeMcC399]

Where to find the issue

https://www.coronawarn.app/en/faq/#googleplay

Describe the issue

FAQ article [Google/Android]: Why are Android 6 and Google Play Services minimum requirements?

"Google delivers the required Exposure Notification API for contact tracing apps with Google Play Services. The API is supported starting with Android API level 23. This version is available starting with Android version 6.0, see Codenames, Tags, and Build Numbers. This was decided solely by Google. In addition, older devices sometimes don’t support Bluetooth Low Energy. We as app developers, unfortunately, cannot influence this."

The above statement about the dependency on the Google Exposure Notifications System does not correspond to the current information in https://developers.google.com/android/exposure-notifications/exposure-notifications-api#architecture which says:

"For your app to work on all devices, set your minSdkVersion to version 6.0 (API level 23) or higher. The framework works on some devices as low as version 5.0 (API level 21), so using this version is an option to increase the number of devices eligible. If you decide to set the minSdkVersion to API level 21, you should test your app on the most popular Android 5.0 devices in your country to ensure that your app works as intended. ... (Last updated 2020-10-22 UTC)"

In the history of the Google Exposure Notifications System it seems that Google changed the minimum API level from 23 to 21, so the statement in the FAQ was probably true at the time of writing, but it is no longer true.

The specification of the Google Exposure Notifications System is no longer a sole justification for CWA not supporting Android 5.0 (API 21) or Android 5.1 (API 22).

The FAQs of the Federal Government https://www.bundesregierung.de/breg-de/themen/corona-warn-app/corona-warn-app-englisch/corona-warn-app-faq-1758636 state:

"The Federal Government has asked the companies involved to conduct a technical review with the manufacturers of the operating systems, to check whether there are further possibilities to also technically integrate older smartphones, and open the interface to them."

Suggested change

CWA development should give an updated status on what prevents CWA supporting Android 5.x. For instance that there are other dependencies such as:
Manifest merger failed : uses-sdk:minSdkVersion 21 cannot be smaller than version 23 declared in library [androidx.security:security-crypto:1.0.0-rc03]

Alternatively, if there are any new plans for being able to support Android 5.x in future, these should be stated.

[MikeJayDee]

ENF for Android was initially (pre-final release) described as working with API version 21 (Android 5.0), but this was changed to API 23 (Android 6.0); there were reports that Apps would work when set to target API version 21. The issue is still open in Google's ENF repository:

https://github.com/google/exposure-notifications-android/issues/16

It seems they have clarified this now. Would be great to support Android 5 and 5.1. Together with iOS 12.5, this should then cover virtually all stock Android and iPhone devices still in use.

Should this maybe not be an issue for the Android app rather than CWA website?

[MikeMcC399]

@MikeJayDee

Should this maybe not be an issue for the Android app rather than CWA website?

It's at least an issue for the FAQ website, because the website says that the app can't support Android 5.0 because Google doesn't support it, which is no longer true.

There are other discussions about the actual support, rather than the documentation of minimum version supported:

• https://github.com/corona-warn-app/cwa-app-android/issues/1799
• https://github.com/corona-warn-app/cwa-app-android/issues/649
• https://github.com/corona-warn-app/cwa-app-android/issues/530
• https://github.com/corona-warn-app/cwa-app-android/issues/165

Most of the above issues were closed due to the information state available at the time of discussion.

In any case it would be invaluable to get development feedback about the feasibility and possible plans to support Android 5.0 (Lollipop) and Android 5.1 (Marshmallow).

[thomasaugsten]

We still investigate the numbers of Android 5 which has the Bluetooth LE advertisement capability and where sold in Germany. From the information of Google this where only a few devices. The next step is a possibility to test this device and filter out non working Android 5 devices on App level.