Fallback onto getName when getCanonicalName returns null

Some Java classes (e.g., anonymous ones) do not have a canonical name.
To support their filtering, fallback onto getName in these scenarios.
We don't just always call getName to minimize unintended changes in
behavior.

Test: TH
Bug: 427875918
Flag: TEST_ONLY
Change-Id: I5581c64fda7ace4bcbb6935dbc4c3d784d2dec91