Is there any way to change App source on Android?
The solution is as simple as a few (s)hell commands. Requires root and BusyBox.

Open a terminal or an adb shell and type

su
sed -i 's/installer="[A-Za-z0-9._-]*"/installer="com.android.vending"/g' /data/system/packages.xml


If the command prompt tells you sed: not found, install BusyBox correctly and prepend busybox before sed.



Be aware that this is a highly dangerous action. It is strongly recommended that you backup the file before attempting to modify it. Also in some cases the file permission may get messed up, fix it by

chmod 0660 /data/system/packages.list
chown 1000.1000 /data/system/packages.list