[Autofill Framework] Add some save related logging

This change adds three log into session comit logger:
1. How many save infos there are in this session
2. How many save data types there are in this session
3. Whether the last fill response has save info

Currently framework is only checking the last fill response for save.
These logs added are for measuring how many benefits it brings for
framework to check previous save info also and whether it benefits to
show save dialogs for different types of data.

Autofill CTS module passes except a known failure:
https://android-build.corp.google.com/test_investigate/?invocationId=I21000010284871536

Bug: b/338600483
Test: atest CtsAutoFillServiceTestCases && local validation with debug
log

Change-Id: I30cd99dacd4d49b021ba66b560c4bce5a66609a3