Allow setting installer / backup installer

[schnatterer]

pm install and install-create provide -i to set installer, e.g. com.android.vending for playstore.

We could expose this param, even better we could back up the installer with the app in a metadata file.

SeedVault does this for example.

Unfortunately, whilst pm install -i seems to work, pm install-create -i seems to have no effect. sudo pm list still shows installer=null on android 14.
To support multiple apks, we have to use install-create, though.
🤷‍♂️