Reset MDD topics manifest url to default after test finished.

It caused other CTS test fail if we don't reset it back. 91/100 passed in abtd test run: http://go/android-investigate?invocationId=I89700010128428989&testResultId=TR77028484660254618

Test: atest

Bug: 267320795, 267408084, 265141725
Change-Id: I50bc86dc2a796dbb131cb51fee4ce887fde51e4a