I noticed that for some system apps (for example Chrome, which is preinstalled by default on my device), I can't do
adb backup. Doing so results in the 47 bytes dummy .ab file. I checked in the manifest and they have
E.g. for Chrome, the content of the manifest is
allowBackup="true" backupAgent="org.chromium.chrome.browser.ChromeBackupAgent" extractNativeLibs="false" fullBackupOnly="false"
Why is this happening? How can I backup such apps' data without root?
P.S. Helium backup doesn't show system apps.