Fix flaky TeleServices tests causing module errors

Some tests were using reflection to replace static instances but not
resetting the previous values, causing the device to remain in a bad
state. Add a replaceInstance and restoreInstances method to
TelephonyTestBase and have these classes extend it so cleanup can be
done in the @After method.
Fix flaky NotificationMgrTests causing module errors due to incomplete
mocks.
Also revert changes added to help debug b/256244889.

Test: atest TeleServiceTests
Bug: 256244889
Change-Id: Id758e207da862f450d5c90971cb3ea1bd2afe40d
7 files changed