Increase app updater balances.

Increase the minimum balances of app updaters in proportion to the
number of apps they're responsible for updating so that it's easier for
them to do app updates in the background.

Bug: 243987091
Test: Manually check balances are adjusted in dump
Test: atest frameworks/base/services/tests/mockingservicestests/src/com/android/server/tare
Test: atest frameworks/base/services/tests/servicestests/src/com/android/server/tare
Change-Id: I0d431f2308b8e4938437d3141318306f96296732