Add a test equivalent to default_log_levels

This is to mainly kill the migrate script logs
but can be used to quieten down any log.
Also the migrations were not using the FakeLogger
so now both are using the same mechanism.

Fixes-bug: 1281226
Change-Id: I2f1efcace6a38450020fcbf516ee5026204359d2
Merge "Add a test equivalent to default_log_levels"