Description of Issue:

beginning in Android 15 foreground services cannot successfully gain audio focus unless they have a visible activity - using AudioManager.requestAudioFocus()

Is this a regression in Android 15?

Yes, Android 14 and prior versions didn't reject audio focus to foreground services

What changed in Android 15?

see Android 15 documentation: Apps that target Android 15 must be the top app or running an audio-related foreground service in order to request audio focus.
BUT, despite the documentation stating that a foreground service can request audio focus, this doesn't appear to be the case - even if the service is using android:foregroundServiceType="mediaPlayback"

Desired Behavior

a foreground service with the proper media-type can successfully request audio focus when an activity is visible or not

Why this is a problem

our alarm app with millions of downloads is unable to successfully request audio focus when an alarm starts, since an activity is not always present due to background start restrictions and the delay associated with setFullScreenIntent()'s lifecycle (and still neither is guaranteed to occur)
this will have an effect on alarm apps and other media apps that can no longer gain audio focus from their foreground services
we have had to pause the release of our Android 15 app update until this is resolved

Sample App

we have created a sample app that illustrates the problem and shared with android-bugreport@google.com here: https://drive.google.com/file/d/16ZlkbO_mcXS3RVaePL-mHgIcF7034JRr/view?usp=sharing
launch the app and click the button (sets an alarm for the AlarmService start in 5s) while activity is still visible - notice error logs in AlarmService show request audio focus was successful
do the same as above, but after clicking the button immediately close the app and remove it from recents - results in failed audio focus when the AlarmService starts

Issue 375228130